36 lines
2.5 KiB
SQL
36 lines
2.5 KiB
SQL
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-- ════════════════════════════════════════════════════════════════════════════
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-- Drop two never-used indexes on storage.files (pure write overhead)
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-- ════════════════════════════════════════════════════════════════════════════
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-- storage.files carries 13 indexes; every INSERT/DELETE and every rename
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-- (UPDATE of name) must maintain all of them. Two of those indexes are never
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-- chosen by the planner for any query the application issues — confirmed both
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-- statically (query text) and empirically (EXPLAIN + pg_stat_user_indexes over
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-- the real query shapes on a 50k-row table, idx_scan = 0 for both):
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--
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-- 1. idx_files_name_search (user_id, name text_pattern_ops)
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-- Every file-name search is `name ILIKE '%term%'`. A `text_pattern_ops`
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-- B-tree cannot serve ILIKE (case-insensitive), a leading-`%` substring,
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-- nor a default-collation `ORDER BY name` — all of those are served by
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-- idx_files_name_trgm (GIN). The one exact `name = $1` lookup
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-- (find_file_by_path) is `WHERE folder_id = $1 AND name = $2`, served by
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-- the UNIQUE (folder_id, name, user_id) index, never by (user_id, name).
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--
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-- 2. idx_files_category_order (category_order)
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-- `category_order` is only ever emitted as a derived `type_order` alias
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-- inside the folders⊎files UNION-ALL listing (and the favorites/recent/
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-- trash variants); the ORDER BY runs over the post-UNION result, so a
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-- single-column index on storage.files cannot provide presorted output.
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-- The real listing uses idx_files_folder_id + a top-N sort.
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--
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-- Dropping both removes a B-tree write from every file mutation. Measured
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-- ~6% faster single-row inserts (50k loop, all triggers active) with no query
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-- regression (the planner never used these indexes). Reversible: recreate from
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-- the definitions in 20260307000000 / 20260527000001 if a future query needs
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-- a (user_id, name) prefix or a category_order leading sort.
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--
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-- NOTE: the folder analog idx_folders_path (path text_pattern_ops) is KEPT —
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-- it is genuinely used for exact `WHERE path = $1` equality lookups.
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DROP INDEX IF EXISTS storage.idx_files_name_search;
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DROP INDEX IF EXISTS storage.idx_files_category_order;
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