pub const LIVE_LEAF_SQL: &str = "b.deleted_commit IS NULL AND NOT EXISTS (SELECT 1 FROM blocks c WHERE c.doc_id = b.doc_id AND c.parent_block = b.block_id AND c.deleted_commit IS NULL)";Expand description
SQL predicate: the blocks row aliased b is a live leaf — no live
row of the same document names it as parent_block (search 1.2: a
container’s text is its children’s text joined, so only leaves are
indexed). c.doc_id = b.doc_id lets the subquery use idx_blocks_doc.