datafusion-ducklake 0.6.0

//! MySQL metadata provider for DuckLake catalogs.

use crate::Result;
use crate::metadata_provider::{
    ColumnWithTable, DataFileChange, DeleteFileChange, DuckLakeFileColumnStatistics,
    DuckLakeFileData, DuckLakeFileMetadata, DuckLakeStatistics, DuckLakeTableColumn,
    DuckLakeTableColumnStatistics, DuckLakeTableFile, DuckLakeTableStatistics, FileWithTable,
    MetadataProvider, SQL_GET_FILE_PARTITION_VALUES, SQL_GET_PARTITION_SPEC, SchemaMetadata,
    SnapshotMetadata, TableMetadata, TableWithSchema, block_on, reconstruct_list_columns,
    reconstruct_list_columns_with_table,
};
use crate::partition::PartitionSpec;
use sqlx::Row;
use sqlx::mysql::{MySqlPool, MySqlPoolOptions, MySqlRow};
use sqlx::types::chrono::NaiveDateTime;
use std::collections::HashMap;
use std::sync::{Arc, OnceLock};

fn is_missing_statistics_table(error: &sqlx::Error) -> bool {
    let message = error.to_string().to_ascii_lowercase();
    message.contains("doesn't exist")
        || message.contains("does not exist")
        || message.contains("unknown table")
}

fn decode_table_file(row: &MySqlRow, snapshot_id: i64) -> Result<DuckLakeTableFile> {
    let delete_file_id: Option<i64> = row.try_get(8)?;
    let (delete_file, delete_count) = if delete_file_id.is_some() {
        (
            Some(DuckLakeFileData {
                path: row.try_get(9)?,
                path_is_relative: row.try_get(10)?,
                file_size_bytes: row.try_get(11)?,
                footer_size: row.try_get(12)?,
                encryption_key: row.try_get(13)?,
            }),
            row.try_get(14)?,
        )
    } else {
        (None, None)
    };
    Ok(DuckLakeTableFile {
        data_file_id: row.try_get(0)?,
        file: DuckLakeFileData {
            path: row.try_get(1)?,
            path_is_relative: row.try_get(2)?,
            file_size_bytes: row.try_get(3)?,
            footer_size: row.try_get(4)?,
            encryption_key: row.try_get(5)?,
        },
        delete_file_id,
        delete_file,
        row_id_start: row.try_get(6)?,
        snapshot_id: Some(snapshot_id),
        begin_snapshot: None,
        schema_version: None,
        partial_max: None,
        max_row_count: row.try_get(7)?,
        delete_count,
        partition_id: None,
        partition_values: Vec::new(),
    })
}

/// Optional catalog-schema capabilities probed before CDC queries.
///
/// Older catalogs may lack the `partial_max` columns; the CDC queries degrade
/// the corresponding projections/predicates to NULL when a capability is
/// absent.
#[derive(Debug, Clone, Copy)]
struct SchemaCapabilities {
    /// `ducklake_data_file.partial_max` exists.
    data_file_partial_max: bool,
    /// `ducklake_delete_file.partial_max` exists.
    delete_file_partial_max: bool,
}

impl SchemaCapabilities {
    fn all(&self) -> bool {
        self.data_file_partial_max && self.delete_file_partial_max
    }
}

/// MySQL-based metadata provider for DuckLake catalogs.
#[derive(Debug, Clone)]
pub struct MySqlMetadataProvider {
    pub pool: MySqlPool,
    // Positive-only memo of the optional-schema capability probes. `Arc` so
    // derived `Clone` shares the cache across provider clones.
    schema_capabilities: Arc<OnceLock<SchemaCapabilities>>,
}

impl MySqlMetadataProvider {
    /// Creates a new provider for an existing DuckLake catalog.
    pub async fn new(connection_string: &str) -> Result<Self> {
        let pool = MySqlPoolOptions::new()
            .max_connections(5)
            .connect(connection_string)
            .await?;

        Ok(Self {
            pool,
            schema_capabilities: Arc::new(OnceLock::new()),
        })
    }

    /// Creates a provider over an existing connection pool. Replaces
    /// struct-literal construction, which stopped compiling when the
    /// schema-capability memo field was added.
    pub fn from_pool(pool: MySqlPool) -> Self {
        Self {
            pool,
            schema_capabilities: Arc::new(OnceLock::new()),
        }
    }

    /// Whether the schema-capability memo is populated. Exposed for tests.
    #[doc(hidden)]
    pub fn schema_capabilities_cached(&self) -> bool {
        self.schema_capabilities.get().is_some()
    }

    /// Returns the catalog's optional-schema capabilities, probing at most
    /// once per provider lifetime on a fully-migrated catalog.
    ///
    /// Cache-positive-only: capability existence is monotonic (migrations only
    /// add columns/tables, never drop them), so an all-`true` answer is an
    /// immutable fact and safe to memoize. A `false` answer is never cached —
    /// the next call re-probes, so a mid-flight catalog upgrade is picked up
    /// on the next call exactly like the previous per-call probing. Concurrent
    /// first calls may each probe once (one statement each) — harmless; a
    /// raced `set` is ignored.
    async fn schema_capabilities(&self) -> Result<SchemaCapabilities> {
        if let Some(caps) = self.schema_capabilities.get() {
            return Ok(*caps);
        }
        let row: (i64, i64) = sqlx::query_as(
            "SELECT
               (SELECT COUNT(*) FROM information_schema.columns
                WHERE table_schema = DATABASE()
                  AND table_name = 'ducklake_data_file'
                  AND column_name = 'partial_max'),
               (SELECT COUNT(*) FROM information_schema.columns
                WHERE table_schema = DATABASE()
                  AND table_name = 'ducklake_delete_file'
                  AND column_name = 'partial_max')",
        )
        .fetch_one(&self.pool)
        .await?;
        let caps = SchemaCapabilities {
            data_file_partial_max: row.0 > 0,
            delete_file_partial_max: row.1 > 0,
        };
        if caps.all() {
            let _ = self.schema_capabilities.set(caps);
        }
        Ok(caps)
    }
}

impl MetadataProvider for MySqlMetadataProvider {
    fn get_current_snapshot(&self) -> Result<i64> {
        block_on(async {
            let row = sqlx::query("SELECT COALESCE(MAX(snapshot_id), 0) FROM ducklake_snapshot")
                .fetch_one(&self.pool)
                .await?;
            Ok(row.try_get(0)?)
        })
    }

    fn get_data_path(&self) -> Result<String> {
        block_on(async {
            let row = sqlx::query(
                "SELECT value FROM ducklake_metadata WHERE `key` = ? AND scope IS NULL",
            )
            .bind("data_path")
            .fetch_optional(&self.pool)
            .await?;

            match row {
                Some(r) => Ok(r.try_get(0)?),
                None => Err(crate::error::DuckLakeError::InvalidConfig(
                    "Missing required catalog metadata: 'data_path' not configured. \
                     The catalog may be uninitialized or corrupted."
                        .to_string(),
                )),
            }
        })
    }

    fn list_snapshots(&self) -> Result<Vec<SnapshotMetadata>> {
        block_on(async {
            let rows = sqlx::query(
                "SELECT snapshot_id, snapshot_time
                 FROM ducklake_snapshot ORDER BY snapshot_id",
            )
            .fetch_all(&self.pool)
            .await?;

            rows.into_iter()
                .map(|row| {
                    let snapshot_id: i64 = row.try_get(0)?;
                    let timestamp: Option<NaiveDateTime> = row.try_get(1)?;
                    let timestamp_str = timestamp
                        .map(|ts: NaiveDateTime| ts.format("%Y-%m-%d %H:%M:%S%.6f").to_string());

                    Ok(SnapshotMetadata {
                        snapshot_id,
                        timestamp: timestamp_str,
                    })
                })
                .collect()
        })
    }

    fn list_schemas(&self, snapshot_id: i64) -> Result<Vec<SchemaMetadata>> {
        block_on(async {
            let rows = sqlx::query(
                "SELECT schema_id, schema_name, path, path_is_relative FROM ducklake_schema
                 WHERE ? >= begin_snapshot AND (? < end_snapshot OR end_snapshot IS NULL)",
            )
            .bind(snapshot_id)
            .bind(snapshot_id)
            .fetch_all(&self.pool)
            .await?;

            rows.into_iter()
                .map(|row| {
                    Ok(SchemaMetadata {
                        schema_id: row.try_get(0)?,
                        schema_name: row.try_get(1)?,
                        path: row.try_get(2)?,
                        path_is_relative: row.try_get(3)?,
                    })
                })
                .collect()
        })
    }

    fn list_tables(&self, schema_id: i64, snapshot_id: i64) -> Result<Vec<TableMetadata>> {
        block_on(async {
            let rows = sqlx::query(
                "SELECT table_id, table_name, path, path_is_relative FROM ducklake_table
                 WHERE schema_id = ?
                   AND ? >= begin_snapshot
                   AND (? < end_snapshot OR end_snapshot IS NULL)",
            )
            .bind(schema_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .fetch_all(&self.pool)
            .await?;

            rows.into_iter()
                .map(|row| {
                    Ok(TableMetadata {
                        table_id: row.try_get(0)?,
                        table_name: row.try_get(1)?,
                        path: row.try_get(2)?,
                        path_is_relative: row.try_get(3)?,
                    })
                })
                .collect()
        })
    }

    fn get_table_structure(
        &self,
        table_id: i64,
        snapshot_id: i64,
    ) -> Result<Vec<DuckLakeTableColumn>> {
        block_on(async {
            let rows = sqlx::query(
                "SELECT column_id, column_name, column_type, nulls_allowed, parent_column
                 FROM ducklake_column
                 WHERE table_id = ?
                   AND ? >= begin_snapshot
                   AND (? < end_snapshot OR end_snapshot IS NULL)
                 ORDER BY column_order",
            )
            .bind(table_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .fetch_all(&self.pool)
            .await?;

            let raw: Result<Vec<(DuckLakeTableColumn, Option<i64>)>> = rows
                .into_iter()
                .map(|row| {
                    let nulls_allowed: Option<bool> = row.try_get(3)?;
                    let parent_column: Option<i64> = row.try_get(4)?;
                    Ok((
                        DuckLakeTableColumn {
                            column_id: row.try_get(0)?,
                            column_name: row.try_get(1)?,
                            column_type: row.try_get(2)?,
                            is_nullable: nulls_allowed.unwrap_or(true),
                        },
                        parent_column,
                    ))
                })
                .collect();
            Ok(reconstruct_list_columns(raw?))
        })
    }

    fn get_table_files_for_select(
        &self,
        table_id: i64,
        snapshot_id: i64,
    ) -> Result<Vec<DuckLakeTableFile>> {
        block_on(async {
            let rows = sqlx::query(
                "SELECT
                    data.data_file_id,
                    data.path AS data_file_path,
                    data.path_is_relative AS data_path_is_relative,
                    data.file_size_bytes AS data_file_size,
                    data.footer_size AS data_footer_size,
                    data.encryption_key AS data_encryption_key,
                    data.row_id_start AS data_row_id_start,
                    data.record_count AS data_record_count,
                    del.delete_file_id,
                    del.path AS delete_file_path,
                    del.path_is_relative AS delete_path_is_relative,
                    del.file_size_bytes AS delete_file_size,
                    del.footer_size AS delete_footer_size,
                    del.encryption_key AS delete_encryption_key,
                    del.delete_count
                FROM ducklake_data_file AS data
                LEFT JOIN ducklake_delete_file AS del
                    ON data.data_file_id = del.data_file_id
                    AND del.table_id = ?
                    AND ? >= del.begin_snapshot
                    AND (? < del.end_snapshot OR del.end_snapshot IS NULL)
                WHERE data.table_id = ?
                  AND ? >= data.begin_snapshot
                  AND (? < data.end_snapshot OR data.end_snapshot IS NULL)",
            )
            .bind(table_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(table_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .fetch_all(&self.pool)
            .await?;

            rows.iter()
                .map(|row| decode_table_file(row, snapshot_id))
                .collect()
        })
    }

    fn get_partition_spec(&self, table_id: i64, snapshot_id: i64) -> Result<Option<PartitionSpec>> {
        block_on(async {
            // Pruning is only safe with exactly one spec generation ever (see
            // PartitionSpec::prune_safe); the live spec is returned regardless so
            // the write path always targets the current generation.
            let generation_count: i64 = match sqlx::query_scalar(
                "SELECT COUNT(*) FROM ducklake_partition_info WHERE table_id = ?",
            )
            .bind(table_id)
            .fetch_one(&self.pool)
            .await
            {
                Ok(count) => count,
                Err(error) if is_missing_statistics_table(&error) => return Ok(None),
                Err(error) => return Err(error.into()),
            };
            let prune_safe = generation_count == 1;
            let rows = match sqlx::query(SQL_GET_PARTITION_SPEC)
                .bind(table_id)
                .bind(snapshot_id)
                .bind(snapshot_id)
                .fetch_all(&self.pool)
                .await
            {
                Ok(rows) => rows,
                Err(error) if is_missing_statistics_table(&error) => return Ok(None),
                Err(error) => return Err(error.into()),
            };
            let parsed = rows
                .iter()
                .map(|row| {
                    Ok::<_, crate::DuckLakeError>((
                        row.try_get::<i64, _>(0)?,
                        i32::try_from(row.try_get::<i64, _>(1)?).unwrap_or(0),
                        row.try_get::<i64, _>(2)?,
                        row.try_get::<String, _>(3)?,
                    ))
                })
                .collect::<Result<Vec<_>>>()?;
            Ok(PartitionSpec::from_rows(parsed, prune_safe))
        })
    }

    fn get_table_file_metadata_page(
        &self,
        table_id: i64,
        snapshot_id: i64,
        after_data_file_id: Option<i64>,
        limit: usize,
    ) -> Result<Vec<DuckLakeFileMetadata>> {
        if limit == 0 {
            return Ok(Vec::new());
        }
        let limit = i64::try_from(limit).map_err(|_| {
            crate::DuckLakeError::InvalidConfig("file metadata page limit exceeds i64".to_string())
        })?;
        block_on(async {
            let rows = sqlx::query(
                "SELECT data.data_file_id, data.path, data.path_is_relative,
                        data.file_size_bytes, data.footer_size, data.encryption_key,
                        data.row_id_start, data.record_count,
                        del.delete_file_id, del.path, del.path_is_relative,
                        del.file_size_bytes, del.footer_size, del.encryption_key,
                        del.delete_count
                 FROM ducklake_data_file AS data
                 LEFT JOIN ducklake_delete_file AS del
                   ON data.data_file_id = del.data_file_id
                  AND del.table_id = ?
                  AND ? >= del.begin_snapshot
                  AND (? < del.end_snapshot OR del.end_snapshot IS NULL)
                 WHERE data.table_id = ?
                   AND ? >= data.begin_snapshot
                   AND (? < data.end_snapshot OR data.end_snapshot IS NULL)
                   AND data.data_file_id > ?
                 ORDER BY data.data_file_id
                 LIMIT ?",
            )
            .bind(table_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(table_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(after_data_file_id.unwrap_or(i64::MIN))
            .bind(limit)
            .fetch_all(&self.pool)
            .await?;
            let files = rows
                .iter()
                .map(|row| decode_table_file(row, snapshot_id))
                .collect::<Result<Vec<_>>>()?;
            let Some(last_data_file_id) = files.last().map(|file| file.data_file_id) else {
                return Ok(Vec::new());
            };
            let statistics = match sqlx::query(
                "SELECT stats.data_file_id, stats.column_id,
                        stats.column_size_bytes, stats.value_count, stats.null_count,
                        stats.min_value, stats.max_value
                 FROM ducklake_file_column_stats AS stats
                 INNER JOIN ducklake_data_file AS data
                   ON data.data_file_id = stats.data_file_id
                  AND data.table_id = stats.table_id
                 WHERE stats.table_id = ?
                   AND ? >= data.begin_snapshot
                   AND (? < data.end_snapshot OR data.end_snapshot IS NULL)
                   AND stats.data_file_id > ?
                   AND stats.data_file_id <= ?
                 ORDER BY stats.data_file_id, stats.column_id",
            )
            .bind(table_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(after_data_file_id.unwrap_or(i64::MIN))
            .bind(last_data_file_id)
            .fetch_all(&self.pool)
            .await
            {
                Ok(rows) => rows
                    .into_iter()
                    .map(|row| {
                        Ok(DuckLakeFileColumnStatistics {
                            data_file_id: row.try_get(0)?,
                            column_id: row.try_get(1)?,
                            column_size_bytes: row.try_get(2)?,
                            value_count: row.try_get(3)?,
                            null_count: row.try_get(4)?,
                            min_value: row.try_get(5)?,
                            max_value: row.try_get(6)?,
                        })
                    })
                    .collect::<Result<Vec<_>>>()?,
                Err(error) if is_missing_statistics_table(&error) => Vec::new(),
                Err(error) => return Err(error.into()),
            };
            let mut statistics_by_file: HashMap<i64, Vec<_>> = HashMap::new();
            for statistic in statistics {
                statistics_by_file
                    .entry(statistic.data_file_id)
                    .or_default()
                    .push(statistic);
            }

            // Enrich with per-file partition values (for pruning), scoped to the
            // page's data_file_id range. Missing partition table => no enrichment.
            let mut values_by_file: HashMap<i64, Vec<(i32, Option<String>)>> = HashMap::new();
            match sqlx::query(SQL_GET_FILE_PARTITION_VALUES)
                .bind(table_id)
                .bind(after_data_file_id.unwrap_or(i64::MIN))
                .bind(last_data_file_id)
                .fetch_all(&self.pool)
                .await
            {
                Ok(rows) => {
                    for row in rows {
                        let data_file_id: i64 = row.try_get(0)?;
                        let key_index: i32 = i32::try_from(row.try_get::<i64, _>(1)?).unwrap_or(0);
                        let value: Option<String> = row.try_get(2)?;
                        values_by_file
                            .entry(data_file_id)
                            .or_default()
                            .push((key_index, value));
                    }
                },
                Err(error) if is_missing_statistics_table(&error) => {},
                Err(error) => return Err(error.into()),
            }

            Ok(files
                .into_iter()
                .map(|mut file| {
                    if let Some(values) = values_by_file.remove(&file.data_file_id) {
                        file.partition_values = values;
                    }
                    DuckLakeFileMetadata {
                        column_statistics: statistics_by_file
                            .remove(&file.data_file_id)
                            .unwrap_or_default(),
                        file,
                    }
                })
                .collect())
        })
    }

    fn get_table_summary_statistics(
        &self,
        table_id: i64,
        snapshot_id: i64,
    ) -> Result<DuckLakeStatistics> {
        block_on(async {
            let table = match sqlx::query(
                "SELECT record_count, file_size_bytes
                 FROM ducklake_table_stats WHERE table_id = ?",
            )
            .bind(table_id)
            .fetch_optional(&self.pool)
            .await
            {
                Ok(row) => row
                    .map(|row| {
                        Ok::<_, sqlx::Error>(DuckLakeTableStatistics {
                            record_count: row.try_get(0)?,
                            file_size_bytes: row.try_get(1)?,
                        })
                    })
                    .transpose()?,
                Err(error) if is_missing_statistics_table(&error) => None,
                Err(error) => return Err(error.into()),
            };
            let column_sizes = match sqlx::query(
                "SELECT stats.column_id,
                        CASE
                          WHEN COUNT(*) = COUNT(stats.column_size_bytes)
                           AND COUNT(*) = (
                             SELECT COUNT(*) FROM ducklake_data_file visible
                             WHERE visible.table_id = ?
                               AND ? >= visible.begin_snapshot
                               AND (? < visible.end_snapshot OR visible.end_snapshot IS NULL)
                           )
                          THEN CAST(SUM(stats.column_size_bytes) AS SIGNED)
                        END
                 FROM ducklake_file_column_stats stats
                 INNER JOIN ducklake_data_file data
                   ON data.data_file_id = stats.data_file_id
                  AND data.table_id = stats.table_id
                 WHERE stats.table_id = ?
                   AND ? >= data.begin_snapshot
                   AND (? < data.end_snapshot OR data.end_snapshot IS NULL)
                 GROUP BY stats.column_id",
            )
            .bind(table_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(table_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .fetch_all(&self.pool)
            .await
            {
                Ok(rows) => rows
                    .into_iter()
                    .filter_map(|row| match row.try_get::<Option<i64>, _>(1) {
                        Ok(Some(size)) => Some(row.try_get(0).map(|column_id| (column_id, size))),
                        Ok(None) => None,
                        Err(error) => Some(Err(error)),
                    })
                    .collect::<std::result::Result<HashMap<i64, i64>, _>>()?,
                Err(error) if is_missing_statistics_table(&error) => HashMap::new(),
                Err(error) => return Err(error.into()),
            };
            let bounds_are_exact: bool = sqlx::query_scalar(
                "SELECT NOT EXISTS (
                     SELECT 1 FROM ducklake_delete_file
                     WHERE table_id = ?
                       AND ? >= begin_snapshot
                       AND (? < end_snapshot OR end_snapshot IS NULL)
                 )",
            )
            .bind(table_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .fetch_one(&self.pool)
            .await?;
            let columns = match sqlx::query(
                "SELECT column_id, contains_null, min_value, max_value
                 FROM ducklake_table_column_stats WHERE table_id = ?",
            )
            .bind(table_id)
            .fetch_all(&self.pool)
            .await
            {
                Ok(rows) => rows
                    .into_iter()
                    .map(|row| {
                        let column_id = row.try_get(0)?;
                        Ok(DuckLakeTableColumnStatistics {
                            column_id,
                            contains_null: row.try_get(1)?,
                            min_value: row.try_get(2)?,
                            max_value: row.try_get(3)?,
                            column_size_bytes: column_sizes.get(&column_id).copied(),
                            bounds_are_exact,
                        })
                    })
                    .collect::<Result<Vec<_>>>()?,
                Err(error) if is_missing_statistics_table(&error) => Vec::new(),
                Err(error) => return Err(error.into()),
            };
            Ok(DuckLakeStatistics {
                table,
                columns,
                files: Vec::new(),
            })
        })
    }

    fn get_table_statistics(&self, table_id: i64, snapshot_id: i64) -> Result<DuckLakeStatistics> {
        block_on(async {
            let table = match sqlx::query(
                "SELECT record_count, file_size_bytes
                 FROM ducklake_table_stats WHERE table_id = ?",
            )
            .bind(table_id)
            .fetch_optional(&self.pool)
            .await
            {
                Ok(row) => row
                    .map(|row| {
                        Ok::<_, sqlx::Error>(DuckLakeTableStatistics {
                            record_count: row.try_get(0)?,
                            file_size_bytes: row.try_get(1)?,
                        })
                    })
                    .transpose()?,
                Err(error) if is_missing_statistics_table(&error) => None,
                Err(error) => return Err(error.into()),
            };

            let columns = match sqlx::query(
                "SELECT column_id, contains_null, min_value, max_value
                 FROM ducklake_table_column_stats WHERE table_id = ?",
            )
            .bind(table_id)
            .fetch_all(&self.pool)
            .await
            {
                Ok(rows) => rows
                    .into_iter()
                    .map(|row| {
                        Ok(DuckLakeTableColumnStatistics {
                            column_id: row.try_get(0)?,
                            contains_null: row.try_get(1)?,
                            min_value: row.try_get(2)?,
                            max_value: row.try_get(3)?,
                            column_size_bytes: None,
                            bounds_are_exact: false,
                        })
                    })
                    .collect::<Result<Vec<_>>>()?,
                Err(error) if is_missing_statistics_table(&error) => Vec::new(),
                Err(error) => return Err(error.into()),
            };

            let files = match sqlx::query(
                "SELECT
                    stats.data_file_id,
                    stats.column_id,
                    stats.column_size_bytes,
                    stats.value_count,
                    stats.null_count,
                    stats.min_value,
                    stats.max_value
                 FROM ducklake_file_column_stats AS stats
                 INNER JOIN ducklake_data_file AS data
                    ON data.data_file_id = stats.data_file_id
                    AND data.table_id = stats.table_id
                 WHERE stats.table_id = ?
                   AND ? >= data.begin_snapshot
                   AND (? < data.end_snapshot OR data.end_snapshot IS NULL)",
            )
            .bind(table_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .fetch_all(&self.pool)
            .await
            {
                Ok(rows) => rows
                    .into_iter()
                    .map(|row| {
                        Ok(DuckLakeFileColumnStatistics {
                            data_file_id: row.try_get(0)?,
                            column_id: row.try_get(1)?,
                            column_size_bytes: row.try_get(2)?,
                            value_count: row.try_get(3)?,
                            null_count: row.try_get(4)?,
                            min_value: row.try_get(5)?,
                            max_value: row.try_get(6)?,
                        })
                    })
                    .collect::<Result<Vec<_>>>()?,
                Err(error) if is_missing_statistics_table(&error) => Vec::new(),
                Err(error) => return Err(error.into()),
            };

            Ok(DuckLakeStatistics {
                table,
                columns,
                files,
            })
        })
    }

    fn get_schema_by_name(&self, name: &str, snapshot_id: i64) -> Result<Option<SchemaMetadata>> {
        block_on(async {
            let row = sqlx::query(
                "SELECT schema_id, schema_name, path, path_is_relative FROM ducklake_schema
                 WHERE schema_name = ?
                   AND ? >= begin_snapshot
                   AND (? < end_snapshot OR end_snapshot IS NULL)",
            )
            .bind(name)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .fetch_optional(&self.pool)
            .await?;

            match row {
                Some(r) => Ok(Some(SchemaMetadata {
                    schema_id: r.try_get(0)?,
                    schema_name: r.try_get(1)?,
                    path: r.try_get(2)?,
                    path_is_relative: r.try_get(3)?,
                })),
                None => Ok(None),
            }
        })
    }

    fn get_table_by_name(
        &self,
        schema_id: i64,
        name: &str,
        snapshot_id: i64,
    ) -> Result<Option<TableMetadata>> {
        block_on(async {
            let row = sqlx::query(
                "SELECT table_id, table_name, path, path_is_relative FROM ducklake_table
                 WHERE schema_id = ?
                   AND table_name = ?
                   AND ? >= begin_snapshot
                   AND (? < end_snapshot OR end_snapshot IS NULL)",
            )
            .bind(schema_id)
            .bind(name)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .fetch_optional(&self.pool)
            .await?;

            match row {
                Some(r) => Ok(Some(TableMetadata {
                    table_id: r.try_get(0)?,
                    table_name: r.try_get(1)?,
                    path: r.try_get(2)?,
                    path_is_relative: r.try_get(3)?,
                })),
                None => Ok(None),
            }
        })
    }

    fn table_exists(&self, schema_id: i64, name: &str, snapshot_id: i64) -> Result<bool> {
        block_on(async {
            // MySQL doesn't support SELECT EXISTS(...) the same way PostgreSQL does
            // Use COUNT instead
            let row = sqlx::query(
                "SELECT COUNT(*) FROM ducklake_table
                 WHERE schema_id = ?
                   AND table_name = ?
                   AND ? >= begin_snapshot
                   AND (? < end_snapshot OR end_snapshot IS NULL)",
            )
            .bind(schema_id)
            .bind(name)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .fetch_one(&self.pool)
            .await?;

            let count: i64 = row.try_get(0)?;
            Ok(count > 0)
        })
    }

    fn list_all_tables(&self, snapshot_id: i64) -> Result<Vec<TableWithSchema>> {
        block_on(async {
            let rows = sqlx::query(
                "SELECT s.schema_name, t.table_id, t.table_name, t.path, t.path_is_relative
                 FROM ducklake_schema s
                 JOIN ducklake_table t ON s.schema_id = t.schema_id
                 WHERE ? >= s.begin_snapshot
                   AND (? < s.end_snapshot OR s.end_snapshot IS NULL)
                   AND ? >= t.begin_snapshot
                   AND (? < t.end_snapshot OR t.end_snapshot IS NULL)
                 ORDER BY s.schema_name, t.table_name",
            )
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .fetch_all(&self.pool)
            .await?;

            rows.into_iter()
                .map(|row| {
                    let schema_name: String = row.try_get(0)?;
                    let table = TableMetadata {
                        table_id: row.try_get(1)?,
                        table_name: row.try_get(2)?,
                        path: row.try_get(3)?,
                        path_is_relative: row.try_get(4)?,
                    };
                    Ok(TableWithSchema {
                        schema_name,
                        table,
                    })
                })
                .collect()
        })
    }

    fn list_all_columns(&self, snapshot_id: i64) -> Result<Vec<ColumnWithTable>> {
        block_on(async {
            let rows = sqlx::query(
                "SELECT s.schema_name, t.table_name, c.column_id, c.column_name, c.column_type, c.nulls_allowed, c.parent_column
                 FROM ducklake_schema s
                 JOIN ducklake_table t ON s.schema_id = t.schema_id
                 JOIN ducklake_column c ON t.table_id = c.table_id
                 WHERE ? >= s.begin_snapshot
                   AND (? < s.end_snapshot OR s.end_snapshot IS NULL)
                   AND ? >= t.begin_snapshot
                   AND (? < t.end_snapshot OR t.end_snapshot IS NULL)
                   AND ? >= c.begin_snapshot
                   AND (? < c.end_snapshot OR c.end_snapshot IS NULL)
                 ORDER BY s.schema_name, t.table_name, c.column_order",
            )
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .fetch_all(&self.pool)
            .await?;

            let raw: Result<Vec<(ColumnWithTable, Option<i64>)>> = rows
                .into_iter()
                .map(|row| {
                    let schema_name: String = row.try_get(0)?;
                    let table_name: String = row.try_get(1)?;
                    let nulls_allowed: Option<bool> = row.try_get(5)?;
                    let parent_column: Option<i64> = row.try_get(6)?;
                    let column = DuckLakeTableColumn {
                        column_id: row.try_get(2)?,
                        column_name: row.try_get(3)?,
                        column_type: row.try_get(4)?,
                        is_nullable: nulls_allowed.unwrap_or(true),
                    };
                    Ok((
                        ColumnWithTable {
                            schema_name,
                            table_name,
                            column,
                        },
                        parent_column,
                    ))
                })
                .collect();
            Ok(reconstruct_list_columns_with_table(raw?))
        })
    }

    fn list_all_files(&self, snapshot_id: i64) -> Result<Vec<FileWithTable>> {
        block_on(async {
            let rows = sqlx::query(
                "SELECT
                    s.schema_name,
                    t.table_name,
                    data.data_file_id,
                    data.path AS data_file_path,
                    data.path_is_relative AS data_path_is_relative,
                    data.file_size_bytes AS data_file_size,
                    data.footer_size AS data_footer_size,
                    data.encryption_key AS data_encryption_key,
                    del.delete_file_id,
                    del.path AS delete_file_path,
                    del.path_is_relative AS delete_path_is_relative,
                    del.file_size_bytes AS delete_file_size,
                    del.footer_size AS delete_footer_size,
                    del.encryption_key AS delete_encryption_key,
                    del.delete_count
                FROM ducklake_schema s
                JOIN ducklake_table t ON s.schema_id = t.schema_id
                JOIN ducklake_data_file data ON t.table_id = data.table_id
                LEFT JOIN ducklake_delete_file del
                    ON data.data_file_id = del.data_file_id
                    AND del.table_id = t.table_id
                    AND ? >= del.begin_snapshot
                    AND (? < del.end_snapshot OR del.end_snapshot IS NULL)
                WHERE ? >= s.begin_snapshot
                  AND (? < s.end_snapshot OR s.end_snapshot IS NULL)
                  AND ? >= t.begin_snapshot
                  AND (? < t.end_snapshot OR t.end_snapshot IS NULL)
                  AND ? >= data.begin_snapshot
                  AND (? < data.end_snapshot OR data.end_snapshot IS NULL)
                ORDER BY s.schema_name, t.table_name, data.path",
            )
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .bind(snapshot_id)
            .fetch_all(&self.pool)
            .await?;

            rows.into_iter()
                .map(|row| {
                    let data_file = DuckLakeFileData {
                        path: row.try_get(3)?,
                        path_is_relative: row.try_get(4)?,
                        file_size_bytes: row.try_get(5)?,
                        footer_size: row.try_get(6)?,
                        encryption_key: row.try_get(7)?,
                    };

                    let delete_file = if row.try_get::<Option<i64>, _>(8)?.is_some() {
                        Some(DuckLakeFileData {
                            path: row.try_get(9)?,
                            path_is_relative: row.try_get(10)?,
                            file_size_bytes: row.try_get(11)?,
                            footer_size: row.try_get(12)?,
                            encryption_key: row.try_get(13)?,
                        })
                    } else {
                        None
                    };

                    Ok(FileWithTable {
                        schema_name: row.try_get(0)?,
                        table_name: row.try_get(1)?,
                        file: DuckLakeTableFile {
                            data_file_id: row.try_get(2)?,
                            file: data_file,
                            delete_file_id: row.try_get(8)?,
                            delete_file,
                            row_id_start: None,
                            snapshot_id: None,
                            begin_snapshot: None,
                            schema_version: None,
                            partial_max: None,
                            max_row_count: row.try_get(14)?,
                            delete_count: None,
                            partition_id: None,
                            partition_values: Vec::new(),
                        },
                    })
                })
                .collect()
        })
    }

    fn get_data_files_added_between_snapshots(
        &self,
        table_id: i64,
        start_snapshot: i64,
        end_snapshot: i64,
    ) -> Result<Vec<DataFileChange>> {
        block_on(async {
            // Older catalogs predate `partial_max`; degrade it to NULL there
            // (they cannot contain partial files).
            let pm = if self.schema_capabilities().await?.data_file_partial_max {
                "data.partial_max"
            } else {
                "NULL"
            };
            let rows = sqlx::query(&format!(
                "SELECT
                    data.begin_snapshot,
                    data.path,
                    data.path_is_relative,
                    data.file_size_bytes,
                    data.footer_size,
                    data.encryption_key,
                    data.row_id_start,
                    {pm}
                FROM ducklake_data_file AS data
                WHERE data.table_id = ?
                  AND data.begin_snapshot <= ?
                  AND (data.begin_snapshot >= ?
                       OR ({pm} IS NOT NULL AND {pm} >= ?))
                ORDER BY data.begin_snapshot"
            ))
            .bind(table_id)
            .bind(end_snapshot)
            .bind(start_snapshot)
            .bind(start_snapshot)
            .fetch_all(&self.pool)
            .await?;

            rows.into_iter()
                .map(|row| {
                    Ok(DataFileChange {
                        begin_snapshot: row.try_get(0)?,
                        path: row.try_get(1)?,
                        path_is_relative: row.try_get(2)?,
                        file_size_bytes: row.try_get(3)?,
                        footer_size: row.try_get(4)?,
                        encryption_key: row.try_get(5)?,
                        row_id_start: row.try_get(6)?,
                        partial_max: row.try_get(7)?,
                    })
                })
                .collect()
        })
    }

    fn get_delete_files_added_between_snapshots(
        &self,
        table_id: i64,
        start_snapshot: i64,
        end_snapshot: i64,
    ) -> Result<Vec<DeleteFileChange>> {
        block_on(async {
            // MySQL equivalent of DuckDB's SQL_GET_DELETE_FILES_ADDED_BETWEEN_SNAPSHOTS
            // Uses LATERAL (supported in MySQL 8.0.14+) for previous delete file lookup
            //
            // Cumulative (current-spec) delete files can hold in-window deletions
            // even when their begin_snapshot predates the window; included via
            // `ducklake_delete_file.partial_max`. Older catalogs lack the column
            // (and cumulative delete files); degrade it to NULL there.
            let pm = if self.schema_capabilities().await?.delete_file_partial_max {
                "ddf.partial_max"
            } else {
                "NULL"
            };
            let rows = sqlx::query(&format!(
                r#"
WITH current_delete AS (
    SELECT
        ddf.data_file_id,
        ddf.begin_snapshot,
        ddf.path,
        ddf.path_is_relative,
        ddf.file_size_bytes,
        ddf.footer_size,
        ddf.encryption_key
    FROM ducklake_delete_file ddf
    WHERE ddf.table_id = ?
      AND ddf.begin_snapshot <= ?
      AND (ddf.begin_snapshot >= ?
           OR ({pm} IS NOT NULL AND {pm} >= ?))
),

data_files AS (
    SELECT df.*
    FROM ducklake_data_file df
    WHERE df.table_id = ?
)

-- Part 1: Incremental deletes
SELECT
    data.path,
    data.path_is_relative,
    data.file_size_bytes,
    data.footer_size,
    data.row_id_start,
    data.record_count,
    data.mapping_id,
    current_delete.path,
    current_delete.path_is_relative,
    current_delete.file_size_bytes,
    current_delete.footer_size,
    prev.path,
    prev.path_is_relative,
    prev.file_size_bytes,
    prev.footer_size,
    current_delete.begin_snapshot
FROM current_delete
JOIN data_files data USING (data_file_id)
LEFT JOIN LATERAL (
    SELECT
        ddf.path,
        ddf.path_is_relative,
        ddf.file_size_bytes,
        ddf.footer_size
    FROM ducklake_delete_file ddf
    WHERE ddf.table_id = ?
      AND ddf.data_file_id = current_delete.data_file_id
      AND ddf.begin_snapshot < current_delete.begin_snapshot
    ORDER BY ddf.begin_snapshot DESC
    LIMIT 1
) prev ON true

UNION ALL

-- Part 2: Full file deletes
SELECT
    data.path,
    data.path_is_relative,
    data.file_size_bytes,
    data.footer_size,
    data.row_id_start,
    data.record_count,
    data.mapping_id,
    NULL,
    NULL,
    NULL,
    NULL,
    prev.path,
    prev.path_is_relative,
    prev.file_size_bytes,
    prev.footer_size,
    data.end_snapshot
FROM ducklake_data_file data
LEFT JOIN LATERAL (
    SELECT
        ddf.path,
        ddf.path_is_relative,
        ddf.file_size_bytes,
        ddf.footer_size
    FROM ducklake_delete_file ddf
    WHERE ddf.table_id = ?
      AND ddf.data_file_id = data.data_file_id
      AND ddf.begin_snapshot < data.end_snapshot
    ORDER BY ddf.begin_snapshot DESC
    LIMIT 1
) prev ON true
WHERE data.table_id = ?
  AND data.end_snapshot >= ?
  AND data.end_snapshot <= ?
"#
            ))
            // Part 1 bindings: table_id (current_delete), end, start (window),
            // start (partial_max), table_id (data_files), table_id (prev lateral)
            .bind(table_id)
            .bind(end_snapshot)
            .bind(start_snapshot)
            .bind(start_snapshot)
            .bind(table_id)
            .bind(table_id)
            // Part 2 bindings: table_id (prev lateral), table_id (data), start_snapshot, end_snapshot
            .bind(table_id)
            .bind(table_id)
            .bind(start_snapshot)
            .bind(end_snapshot)
            .fetch_all(&self.pool)
            .await?;

            rows.into_iter()
                .map(|row| {
                    Ok(DeleteFileChange {
                        // data file
                        data_file_path: row.try_get(0)?,
                        data_file_path_is_relative: row.try_get(1)?,
                        data_file_size_bytes: row.try_get(2)?,
                        data_file_footer_size: row.try_get(3)?,
                        data_row_id_start: row.try_get(4)?,
                        data_record_count: row.try_get(5)?,
                        data_mapping_id: row.try_get(6)?,

                        // current delete
                        current_delete_path: row.try_get(7)?,
                        current_delete_path_is_relative: row.try_get(8)?,
                        current_delete_file_size_bytes: row.try_get(9)?,
                        current_delete_footer_size: row.try_get(10)?,

                        // previous delete
                        previous_delete_path: row.try_get(11)?,
                        previous_delete_path_is_relative: row.try_get(12)?,
                        previous_delete_file_size_bytes: row.try_get(13)?,
                        previous_delete_footer_size: row.try_get(14)?,

                        // snapshot
                        snapshot_id: row.try_get(15)?,
                    })
                })
                .collect()
        })
    }
}