Struct M0004 

pub struct M0004;

Migration that swaps idx_event_type for a composite cursor-scan index.

Changes

• Creates idx_event_type_routing_cursor on (aggregator_type, routing_key, timestamp, timestamp_subsec, version).
• Drops idx_event_type (redundant once the composite index exists — same leading column, planner will use the new one).

Notes

• name is intentionally not part of the index: it is only ever a per-aggregator-branch residual predicate inside an OR, and with the typical small set of event names per aggregator type the residual scan stays cheap.
• The ORDER BY tail stops at version; (timestamp, timestamp_subsec, version) is unique in practice, so the trailing id adds storage without eliminating any sort work.

Dependencies

This migration depends on M0003.

Trait Implementations

impl Migration<MySql> for M0004

fn app(&self) -> &str

Returns the application name associated with the migration. This can be the name of the folder or library where the migration is located.

fn name(&self) -> &str

Returns the migration name, typically the file name without the extension.

fn parents(&self) -> Vec<Box<dyn Migration<MySql>>>

Returns the list of parent migrations that must be applied before this migration can be applied.

fn operations(&self) -> Vec<Box<dyn Operation<MySql>>>

Returns the list of operations that make up the migration.

fn replaces(&self) -> Vec<Box<dyn Migration<DB>>>

Returns the list of migrations that this migration replaces.

fn run_before(&self) -> Vec<Box<dyn Migration<DB>>>

Returns the list of migrations that should be run before this migration when applying. but when reverting this migration these migrations should be reverted after this migration is reverted.

fn is_atomic(&self) -> bool

Indicates whether the migration is atomic. By default, this function returns true, meaning the migration is atomic.

fn is_virtual(&self) -> bool

Indicates whether the migration is virtual. By default, this function returns false, meaning the migration is not virtual.

impl Migration<Postgres> for M0004

fn app(&self) -> &str

Returns the application name associated with the migration. This can be the name of the folder or library where the migration is located.

fn name(&self) -> &str

Returns the migration name, typically the file name without the extension.

fn parents(&self) -> Vec<Box<dyn Migration<Postgres>>>

Returns the list of parent migrations that must be applied before this migration can be applied.

fn operations(&self) -> Vec<Box<dyn Operation<Postgres>>>

Returns the list of operations that make up the migration.

fn replaces(&self) -> Vec<Box<dyn Migration<DB>>>

Returns the list of migrations that this migration replaces.

fn run_before(&self) -> Vec<Box<dyn Migration<DB>>>

Returns the list of migrations that should be run before this migration when applying. but when reverting this migration these migrations should be reverted after this migration is reverted.

fn is_atomic(&self) -> bool

Indicates whether the migration is atomic. By default, this function returns true, meaning the migration is atomic.

fn is_virtual(&self) -> bool

Indicates whether the migration is virtual. By default, this function returns false, meaning the migration is not virtual.

impl Migration<Sqlite> for M0004

fn app(&self) -> &str

Returns the application name associated with the migration. This can be the name of the folder or library where the migration is located.

fn name(&self) -> &str

Returns the migration name, typically the file name without the extension.

fn parents(&self) -> Vec<Box<dyn Migration<Sqlite>>>

Returns the list of parent migrations that must be applied before this migration can be applied.

fn operations(&self) -> Vec<Box<dyn Operation<Sqlite>>>

Returns the list of operations that make up the migration.

fn replaces(&self) -> Vec<Box<dyn Migration<DB>>>

Returns the list of migrations that this migration replaces.

fn run_before(&self) -> Vec<Box<dyn Migration<DB>>>

Returns the list of migrations that should be run before this migration when applying. but when reverting this migration these migrations should be reverted after this migration is reverted.

fn is_atomic(&self) -> bool

Indicates whether the migration is atomic. By default, this function returns true, meaning the migration is atomic.

fn is_virtual(&self) -> bool

Indicates whether the migration is virtual. By default, this function returns false, meaning the migration is not virtual.