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- SELECT current_database(), nspname AS schemaname, tblname, idxname, bs*(relpages)::BIGINT AS real_size,
- bs*(relpages-est_pages)::BIGINT AS extra_size,
- 100 * (relpages-est_pages)::FLOAT / relpages AS extra_ratio,
- fillfactor, bs*(relpages-est_pages_ff) AS bloat_size,
- 100 * (relpages-est_pages_ff)::FLOAT / relpages AS bloat_ratio,
- is_na
- -- , 100-(sub.pst).avg_leaf_density, est_pages, index_tuple_hdr_bm, maxalign, pagehdr, nulldatawidth, nulldatahdrwidth, sub.reltuples, sub.relpages -- (DEBUG INFO)
- FROM (
- SELECT COALESCE(1 +
- CEIL(reltuples/FLOOR((bs-pageopqdata-pagehdr)/(4+nulldatahdrwidth)::FLOAT)), 0 -- ItemIdData size + computed avg size of a tuple (nulldatahdrwidth)
- ) AS est_pages,
- COALESCE(1 +
- CEIL(reltuples/FLOOR((bs-pageopqdata-pagehdr)*fillfactor/(100*(4+nulldatahdrwidth)::FLOAT))), 0
- ) AS est_pages_ff,
- bs, nspname, table_oid, tblname, idxname, relpages, fillfactor, is_na
- -- , stattuple.pgstatindex(quote_ident(nspname)||'.'||quote_ident(idxname)) AS pst, index_tuple_hdr_bm, maxalign, pagehdr, nulldatawidth, nulldatahdrwidth, reltuples -- (DEBUG INFO)
- FROM (
- SELECT maxalign, bs, nspname, tblname, idxname, reltuples, relpages, relam, table_oid, fillfactor,
- ( index_tuple_hdr_bm +
- maxalign - CASE -- Add padding to the index tuple header to align on MAXALIGN
- WHEN index_tuple_hdr_bm%maxalign = 0 THEN maxalign
- ELSE index_tuple_hdr_bm%maxalign
- END
- + nulldatawidth + maxalign - CASE -- Add padding to the data to align on MAXALIGN
- WHEN nulldatawidth = 0 THEN 0
- WHEN nulldatawidth::integer%maxalign = 0 THEN maxalign
- ELSE nulldatawidth::integer%maxalign
- END
- )::NUMERIC AS nulldatahdrwidth, pagehdr, pageopqdata, is_na
- -- , index_tuple_hdr_bm, nulldatawidth -- (DEBUG INFO)
- FROM (
- SELECT
- i.nspname, i.tblname, i.idxname, i.reltuples, i.relpages, i.relam, a.attrelid AS table_oid,
- current_setting('block_size')::NUMERIC AS bs, fillfactor,
- CASE -- MAXALIGN: 4 on 32bits, 8 on 64bits (and mingw32 ?)
- WHEN version() ~ 'mingw32' OR version() ~ '64-bit|x86_64|ppc64|ia64|amd64' THEN 8
- ELSE 4
- END AS maxalign,
- /* per page header, fixed size: 20 for 7.X, 24 for others */
- 24 AS pagehdr,
- /* per page btree opaque data */
- 16 AS pageopqdata,
- /* per tuple header: add IndexAttributeBitMapData if some cols are null-able */
- CASE WHEN MAX(COALESCE(s.null_frac,0)) = 0
- THEN 2 -- IndexTupleData size
- ELSE 2 + (( 32 + 8 - 1 ) / 8) -- IndexTupleData size + IndexAttributeBitMapData size ( max num filed per index + 8 - 1 /8)
- END AS index_tuple_hdr_bm,
- /* data len: we remove null values save space using it fractionnal part from stats */
- SUM( (1-COALESCE(s.null_frac, 0)) * COALESCE(s.avg_width, 1024)) AS nulldatawidth,
- MAX( CASE WHEN a.atttypid = 'pg_catalog.name'::regtype THEN 1 ELSE 0 END ) > 0 AS is_na
- FROM pg_attribute AS a
- JOIN (
- SELECT nspname, tbl.relname AS tblname, idx.relname AS idxname, idx.reltuples, idx.relpages, idx.relam,
- indrelid, indexrelid, indkey::SMALLINT[] AS attnum,
- COALESCE(SUBSTRING(
- array_to_string(idx.reloptions, ' ')
- FROM 'fillfactor=([0-9]+)')::SMALLINT, 90) AS fillfactor
- FROM pg_index
- JOIN pg_class idx ON idx.oid=pg_index.indexrelid
- JOIN pg_class tbl ON tbl.oid=pg_index.indrelid
- JOIN pg_namespace ON pg_namespace.oid = idx.relnamespace
- WHERE pg_index.indisvalid AND tbl.relkind = 'r' AND idx.relpages > 0
- ) AS i ON a.attrelid = i.indexrelid
- JOIN pg_stats AS s ON s.schemaname = i.nspname
- AND ((s.tablename = i.tblname AND s.attname = pg_catalog.pg_get_indexdef(a.attrelid, a.attnum, TRUE)) -- stats from tbl
- OR (s.tablename = i.idxname AND s.attname = a.attname))-- stats from functionnal cols
- JOIN pg_type AS t ON a.atttypid = t.oid
- WHERE a.attnum > 0
- GROUP BY 1, 2, 3, 4, 5, 6, 7, 8, 9
- ) AS s1
- ) AS s2
- JOIN pg_am am ON s2.relam = am.oid WHERE am.amname = 'btree'
- ) AS sub
- -- WHERE NOT is_na
- ORDER BY 2,3,4;
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