Shulou(Shulou.com)06/01 Report--

< 0) { /* not cached yet */ estimate_hash_bucket_stats(root, get_rightop(restrictinfo->

Clause), virtualbuckets, & restrictinfo- > right_mcvfreq, & restrictinfo- > right_bucketsize); thisbucketsize = restrictinfo- > right_bucketsize } thismcvfreq = restrictinfo- > right_mcvfreq;} else {Assert (bms_is_subset (restrictinfo- > left_relids, inner_path- > parent- > relids); / * lefthand side is inner * / thisbucketsize = restrictinfo- > left_bucketsize If (thisbucketsize

< 0) { /* not cached yet */ estimate_hash_bucket_stats(root, get_leftop(restrictinfo->

< 0)(gdb) 3357 estimate_hash_bucket_stats(root,(gdb) 3358 get_rightop(restrictinfo->

Clause), (gdb) 3357 estimate_hash_bucket_stats (root, (gdb) 3362 thisbucketsize = restrictinfo- > right_bucketsize (gdb) p * restrictinfo$17 = {type = T_RestrictInfo, clause = 0x1b87260, is_pushed_down = true, outerjoin_delayed = false, can_join = true, pseudoconstant = false, leakproof = false, security_level = 0, clause_relids = 0x1b87380, required_relids = 0x1b86c68, outer_relids = 0x0, nullable_relids = 0x0, left_relids = 0x1b87340, right_relids = 0x1b87360, orclause = 0x0, parent_ec = 0x1b85b88, eval_cost = {startup = 0, per_tuple = 0.00250000000000001}, per_tuple = 0.0001 Outer_selec =-1, mergeopfamilies = 0x1b873c8, left_ec = 0x1b85b88, right_ec = 0x1b85b88, left_em = 0x1b85d58, right_em = 0x1b85c80, scansel_cache = 0x1b92e50, outer_is_left = true, hashjoinoperator = 98, left_bucketsize =-1, right_bucketsize = 0.00010013016921998598, left_mcvfreq =-1, right_mcvfreq = 0}

The calculation process is similar to the previous introduction, calculating the cost of the expression, etc., you can debug.

The final calculation result

3505} (gdb) p * path$19 = {jpath = {path = {type = T_HashPath, pathtype = T_HashJoin, parent = 0x1b91d30, pathtarget = 0x1b91f68, param_info = 0x0, parallel_aware = false, parallel_safe = true, parallel_workers = 0, rows = 100000, startup_cost = 3465, total_cost = 5386, pathkeys = 0x0}, jointype = JOIN_INNER, inner_unique = false, outerjoinpath = 0x1b866c0, innerjoinpath = 0x1b8e780, joinrestrictinfo = 0x1b92208}, path_hashclauses = 0x1b93200, 0x1b93200 = 2 Inner_rows_total = 100000}

DONE!

IV. Reference materials

Allpaths.c

Cost.h

Costsize.c

PG Document:Query Planning

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