From a2c9ad3f8e87f9c2492511086fcc998e84797e48 Mon Sep 17 00:00:00 2001 From: Peter Geoghegan Date: Wed, 18 Jun 2025 19:32:57 -0400 Subject: [PATCH v5 2/2] Make row compares robust during scans with arrays. Recent nbtree bugfix commit 5f4d98d4 accounted for infinite cycling behavior with row compare quals by refusing to apply forcenonrequired in certain cases involving row compares, but it's not clear that that's truly robust. Testing has shown that a scan with a row compare can still read the same leaf page twice (without the scan direction changing), which isn't supposed to be possible following Postgres 17 commit 5bf748b8. Also, we still allowed a required row compare key to be used in forcenonrequired mode when the key happened to be beyond the pstate.ikey offset, which seems quite brittle (and hard to understand). The forcenonrequired row compare special case kludge was only ever needed because row compare quals have gratuitously inconsistent rules around how scans start (which keys can be used for initial positioning purposes) and how scans end (which keys can set continuescan=false). Quals with redundant keys that could not be eliminated by preprocessing had that same quality to them prior to recent bugfix XXXXX, which made sure that only one key could be used to start and/or end scans. This scheme avoided the same infinite cycling behavior (with redundant keys) that we're concerned about here (with row compare keys). Get rid of the forcenonrequired special case by making it unnecessary. Do so by bringing row compare quals in line with the charter established for all required keys by recent bugfix XXXXX: make _bt_first reliably agree with _bt_check_rowcompare about when and where scans with row compare quals start and end. That way, _bt_advance_array_keys can't get the wrong idea about whether or not another call to _bt_first will at least be able to move the scan to the next leaf page. No infinite cycling is possible, even in the absence of the forcenonrequired hack, since the next _bt_first will now definitely make useful progress. This commit fixes two points of disagreement between _bt_first and _bt_check_rowcompare. Firstly, _bt_check_rowcompare was capable of ending the scan at the point where it needed to compare an ISNULL-marked row compare member that came immediately after a required row compare member. _bt_first now has symmetric handling for NULL row compares. Secondly, _bt_first had its own ideas about which keys were safe to use for initial positioning purposes. It could use fewer or more keys than _bt_check_rowcompare. _bt_first now uses the same requireness markings as _bt_check_rowcompare for this (the same approach that _bt_first takes with every other kind of qual following recent bugfix commit XXXXX). Fixing these inconsistencies necessitates dealing with a related issue with the way that row compares are marked required during preprocessing: we never marked lower-order members as required following 2016 bugfix commit a298a1e0. The approach taken by that bugfix commit was overly conservative. The bug in question was actually an oversight in how _bt_check_rowcompare dealt with tuple NULL values that failed to satisfy a scan key marked required in the opposite scan direction (it was a bug in 2011 commits 6980f817 and 882368e8 -- not in 2006 commit 3a0a16cb). Go back to marking row compare members as required based on the original 2006 rules, and fix the 2016 bug in a more principled way: by limiting use of the "set continuescan=false with a key required in the opposite scan direction upon encountering a NULL tuple value" optimization to the first/most significant row member. It isn't safe to use an implied IS NOT NULL qualifier to end the scan when it comes from the row compare's lower-order member keys. NULLs can legitimately occur between groups of tuples that satisfy the qual as a whole, but that in itself doesn't make it unsafe for a lower-order member key to end the scan. It _is_ safe whenever the key really does detect the absolute end of matching tuples. That's only possible with a lower-order row compare member that's marked required in the _current_ scan direction (not in the other direction). Author: Peter Geoghegan Discussion: https://postgr.es/m/CAH2-Wz=pcijHL_mA0_TJ5LiTB28QpQ0cGtT-ccFV=KzuunNDDQ@mail.gmail.com --- src/backend/access/nbtree/nbtpreprocesskeys.c | 19 +- src/backend/access/nbtree/nbtsearch.c | 245 ++++++++++-------- src/backend/access/nbtree/nbtutils.c | 205 ++++++++------- src/test/regress/expected/btree_index.out | 98 ++++++- src/test/regress/sql/btree_index.sql | 58 ++++- 5 files changed, 406 insertions(+), 219 deletions(-) diff --git a/src/backend/access/nbtree/nbtpreprocesskeys.c b/src/backend/access/nbtree/nbtpreprocesskeys.c index ca2a9050f..76cd1ee78 100644 --- a/src/backend/access/nbtree/nbtpreprocesskeys.c +++ b/src/backend/access/nbtree/nbtpreprocesskeys.c @@ -792,12 +792,25 @@ _bt_mark_scankey_required(ScanKey skey) if (skey->sk_flags & SK_ROW_HEADER) { ScanKey subkey = (ScanKey) DatumGetPointer(skey->sk_argument); + AttrNumber attno = skey->sk_attno; /* First subkey should be same column/operator as the header */ - Assert(subkey->sk_flags & SK_ROW_MEMBER); - Assert(subkey->sk_attno == skey->sk_attno); + Assert(subkey->sk_attno == attno); Assert(subkey->sk_strategy == skey->sk_strategy); - subkey->sk_flags |= addflags; + + for (;;) + { + Assert(subkey->sk_flags & SK_ROW_MEMBER); + if (subkey->sk_attno != attno) + break; /* non-adjacent key, so not required */ + if (subkey->sk_strategy != skey->sk_strategy) + break; /* wrong direction, so not required */ + subkey->sk_flags |= addflags; + if (subkey->sk_flags & SK_ROW_END) + break; + subkey++; + attno++; + } } } diff --git a/src/backend/access/nbtree/nbtsearch.c b/src/backend/access/nbtree/nbtsearch.c index 9846ef6db..905f2a3b7 100644 --- a/src/backend/access/nbtree/nbtsearch.c +++ b/src/backend/access/nbtree/nbtsearch.c @@ -1016,8 +1016,8 @@ _bt_first(IndexScanDesc scan, ScanDirection dir) * traversing a lot of null entries at the start of the scan. * * In this loop, row-comparison keys are treated the same as keys on their - * first (leftmost) columns. We'll add on lower-order columns of the row - * comparison below, if possible. + * first (leftmost) columns. We'll add all lower-order columns of the row + * comparison that were marked required during preprocessing below. * * _bt_advance_array_keys needs to know exactly how we'll reposition the * scan (should it opt to schedule another primitive index scan). It is @@ -1261,16 +1261,18 @@ _bt_first(IndexScanDesc scan, ScanDirection dir) Assert(keysz <= INDEX_MAX_KEYS); for (int i = 0; i < keysz; i++) { - ScanKey cur = startKeys[i]; + ScanKey bkey = startKeys[i]; - Assert(cur->sk_attno == i + 1); + Assert(bkey->sk_attno == i + 1); - if (cur->sk_flags & SK_ROW_HEADER) + if (bkey->sk_flags & SK_ROW_HEADER) { /* * Row comparison header: look to the first row member instead */ - ScanKey subkey = (ScanKey) DatumGetPointer(cur->sk_argument); + ScanKey subkey = (ScanKey) DatumGetPointer(bkey->sk_argument); + bool loosen_strat = false, + tighten_strat = false; /* * Cannot be a NULL in the first row member: _bt_preprocess_keys @@ -1278,9 +1280,18 @@ _bt_first(IndexScanDesc scan, ScanDirection dir) * ever getting this far */ Assert(subkey->sk_flags & SK_ROW_MEMBER); - Assert(subkey->sk_attno == cur->sk_attno); + Assert(subkey->sk_attno == bkey->sk_attno); Assert(!(subkey->sk_flags & SK_ISNULL)); + /* + * This is either a > or >= key (during backwards scans it is + * either < or <=) that was marked required during preprocessing. + * Later so->keyData[] keys can't have been marked required, so + * our row compare header key must be the final startKeys[] entry. + */ + Assert(subkey->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD)); + Assert(i == keysz - 1); + /* * The member scankeys are already in insertion format (ie, they * have sk_func = 3-way-comparison function) @@ -1288,112 +1299,141 @@ _bt_first(IndexScanDesc scan, ScanDirection dir) memcpy(inskey.scankeys + i, subkey, sizeof(ScanKeyData)); /* - * If the row comparison is the last positioning key we accepted, - * try to add additional keys from the lower-order row members. - * (If we accepted independent conditions on additional index - * columns, we use those instead --- doesn't seem worth trying to - * determine which is more restrictive.) Note that this is OK - * even if the row comparison is of ">" or "<" type, because the - * condition applied to all but the last row member is effectively - * ">=" or "<=", and so the extra keys don't break the positioning - * scheme. But, by the same token, if we aren't able to use all - * the row members, then the part of the row comparison that we - * did use has to be treated as just a ">=" or "<=" condition, and - * so we'd better adjust strat_total accordingly. + * Now look to later row compare members. + * + * If there's an "index attribute gap" between two row compare + * members, the second member won't have been marked required, and + * so can't be used as starting boundary keys here. The part of + * the row comparison that we do still use has to be treated as a + * ">=" or "<=" condition. For example, a qual "(a, c) > (1, 42)" + * with an omitted intervening index attribute "b" will use an + * insertion scan key "a >= 1". Even the first "a = 1" tuple on + * the leaf level might satisfy the row compare qual. + * + * We're able to use a _more_ restrictive strategy when we reach a + * NULL row compare member, since they're always unsatisfiable. + * For example, a qual "(a, b, c) >= (1, NULL, 77)" will use an + * insertion scan key "a > 1". All tuples where "a = 1" cannot + * possibly satisfy the row compare qual, so this is safe. */ - if (i == keysz - 1) + Assert(!(subkey->sk_flags & SK_ROW_END)); + for (;;) { - bool used_all_subkeys = false; + subkey++; + Assert(subkey->sk_flags & SK_ROW_MEMBER); - Assert(!(subkey->sk_flags & SK_ROW_END)); - for (;;) + if (subkey->sk_flags & SK_ISNULL) { - subkey++; - Assert(subkey->sk_flags & SK_ROW_MEMBER); - if (subkey->sk_attno != keysz + 1) - break; /* out-of-sequence, can't use it */ - if (subkey->sk_strategy != cur->sk_strategy) - break; /* wrong direction, can't use it */ - if (subkey->sk_flags & SK_ISNULL) - break; /* can't use null keys */ - Assert(keysz < INDEX_MAX_KEYS); - memcpy(inskey.scankeys + keysz, subkey, - sizeof(ScanKeyData)); - keysz++; - if (subkey->sk_flags & SK_ROW_END) - { - used_all_subkeys = true; - break; - } + /* + * NULL member key, can only use earlier keys. + * + * We deliberately avoid checking if this key is marked + * required. All earlier keys are required, and this key + * is unsatisfiable either way, so we can't miss anything. + */ + tighten_strat = true; + break; } - if (!used_all_subkeys) + + if (!(subkey->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD))) { - switch (strat_total) - { - case BTLessStrategyNumber: - strat_total = BTLessEqualStrategyNumber; - break; - case BTGreaterStrategyNumber: - strat_total = BTGreaterEqualStrategyNumber; - break; - } + /* nonrequired member key, can only use earlier keys */ + loosen_strat = true; + break; } - break; /* done with outer loop */ + + Assert(subkey->sk_attno == keysz + 1); + Assert(subkey->sk_strategy == bkey->sk_strategy); + Assert(keysz < INDEX_MAX_KEYS); + + memcpy(inskey.scankeys + keysz, subkey, + sizeof(ScanKeyData)); + keysz++; + if (subkey->sk_flags & SK_ROW_END) + break; } + Assert(!(loosen_strat && tighten_strat)); + if (loosen_strat) + { + /* Use less restrictive strategy (and fewer member keys) */ + switch (strat_total) + { + case BTLessStrategyNumber: + strat_total = BTLessEqualStrategyNumber; + break; + case BTGreaterStrategyNumber: + strat_total = BTGreaterEqualStrategyNumber; + break; + } + } + if (tighten_strat) + { + /* Use more restrictive strategy (and fewer member keys) */ + switch (strat_total) + { + case BTLessEqualStrategyNumber: + strat_total = BTLessStrategyNumber; + break; + case BTGreaterEqualStrategyNumber: + strat_total = BTGreaterStrategyNumber; + break; + } + } + + /* done adding to inskey (row comparison keys always come last) */ + break; + } + + /* + * Ordinary comparison key/search-style key. + * + * Transform the search-style scan key to an insertion scan key by + * replacing the sk_func with the appropriate btree 3-way-comparison + * function. + * + * If scankey operator is not a cross-type comparison, we can use the + * cached comparison function; otherwise gotta look it up in the + * catalogs. (That can't lead to infinite recursion, since no + * indexscan initiated by syscache lookup will use cross-data-type + * operators.) + * + * We support the convention that sk_subtype == InvalidOid means the + * opclass input type; this hack simplifies life for ScanKeyInit(). + */ + if (bkey->sk_subtype == rel->rd_opcintype[i] || + bkey->sk_subtype == InvalidOid) + { + FmgrInfo *procinfo; + + procinfo = index_getprocinfo(rel, bkey->sk_attno, BTORDER_PROC); + ScanKeyEntryInitializeWithInfo(inskey.scankeys + i, + bkey->sk_flags, + bkey->sk_attno, + InvalidStrategy, + bkey->sk_subtype, + bkey->sk_collation, + procinfo, + bkey->sk_argument); } else { - /* - * Ordinary comparison key. Transform the search-style scan key - * to an insertion scan key by replacing the sk_func with the - * appropriate btree comparison function. - * - * If scankey operator is not a cross-type comparison, we can use - * the cached comparison function; otherwise gotta look it up in - * the catalogs. (That can't lead to infinite recursion, since no - * indexscan initiated by syscache lookup will use cross-data-type - * operators.) - * - * We support the convention that sk_subtype == InvalidOid means - * the opclass input type; this is a hack to simplify life for - * ScanKeyInit(). - */ - if (cur->sk_subtype == rel->rd_opcintype[i] || - cur->sk_subtype == InvalidOid) - { - FmgrInfo *procinfo; + RegProcedure cmp_proc; - procinfo = index_getprocinfo(rel, cur->sk_attno, BTORDER_PROC); - ScanKeyEntryInitializeWithInfo(inskey.scankeys + i, - cur->sk_flags, - cur->sk_attno, - InvalidStrategy, - cur->sk_subtype, - cur->sk_collation, - procinfo, - cur->sk_argument); - } - else - { - RegProcedure cmp_proc; - - cmp_proc = get_opfamily_proc(rel->rd_opfamily[i], - rel->rd_opcintype[i], - cur->sk_subtype, - BTORDER_PROC); - if (!RegProcedureIsValid(cmp_proc)) - elog(ERROR, "missing support function %d(%u,%u) for attribute %d of index \"%s\"", - BTORDER_PROC, rel->rd_opcintype[i], cur->sk_subtype, - cur->sk_attno, RelationGetRelationName(rel)); - ScanKeyEntryInitialize(inskey.scankeys + i, - cur->sk_flags, - cur->sk_attno, - InvalidStrategy, - cur->sk_subtype, - cur->sk_collation, - cmp_proc, - cur->sk_argument); - } + cmp_proc = get_opfamily_proc(rel->rd_opfamily[i], + rel->rd_opcintype[i], + bkey->sk_subtype, BTORDER_PROC); + if (!RegProcedureIsValid(cmp_proc)) + elog(ERROR, "missing support function %d(%u,%u) for attribute %d of index \"%s\"", + BTORDER_PROC, rel->rd_opcintype[i], bkey->sk_subtype, + bkey->sk_attno, RelationGetRelationName(rel)); + ScanKeyEntryInitialize(inskey.scankeys + i, + bkey->sk_flags, + bkey->sk_attno, + InvalidStrategy, + bkey->sk_subtype, + bkey->sk_collation, + cmp_proc, + bkey->sk_argument); } } @@ -1482,6 +1522,8 @@ _bt_first(IndexScanDesc scan, ScanDirection dir) if (!BufferIsValid(so->currPos.buf)) { + Assert(!so->needPrimScan); + /* * We only get here if the index is completely empty. Lock relation * because nothing finer to lock exists. Without a buffer lock, it's @@ -1500,7 +1542,6 @@ _bt_first(IndexScanDesc scan, ScanDirection dir) if (!BufferIsValid(so->currPos.buf)) { - Assert(!so->needPrimScan); _bt_parallel_done(scan); return false; } diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c index eb6dbfda3..57d76a8d4 100644 --- a/src/backend/access/nbtree/nbtutils.c +++ b/src/backend/access/nbtree/nbtutils.c @@ -2443,31 +2443,9 @@ _bt_set_startikey(IndexScanDesc scan, BTReadPageState *pstate) if (key->sk_flags & SK_ROW_HEADER) { /* - * RowCompare inequality. - * - * Only the first subkey from a RowCompare can ever be marked - * required (that happens when the row header is marked required). - * There is no simple, general way for us to transitively deduce - * whether or not every tuple on the page satisfies a RowCompare - * key based only on firsttup and lasttup -- so we just give up. + * RowCompare inequality. Currently, we just punt on these. */ - if (!start_past_saop_eq && !so->skipScan) - break; /* unsafe to go further */ - - /* - * We have to be even more careful with RowCompares that come - * after an array: we assume it's unsafe to even bypass the array. - * Calling _bt_start_array_keys to recover the scan's arrays - * following use of forcenonrequired mode isn't compatible with - * _bt_check_rowcompare's continuescan=false behavior with NULL - * row compare members. _bt_advance_array_keys must not make a - * decision on the basis of a key not being satisfied in the - * opposite-to-scan direction until the scan reaches a leaf page - * where the same key begins to be satisfied in scan direction. - * The _bt_first !used_all_subkeys behavior makes this limitation - * hard to work around some other way. - */ - return; /* completely unsafe to set pstate.startikey */ + break; /* "unsafe" */ } if (key->sk_strategy != BTEqualStrategyNumber) { @@ -2964,76 +2942,7 @@ _bt_check_rowcompare(ScanKey skey, IndexTuple tuple, int tupnatts, Assert(subkey->sk_flags & SK_ROW_MEMBER); - if (subkey->sk_attno > tupnatts) - { - /* - * This attribute is truncated (must be high key). The value for - * this attribute in the first non-pivot tuple on the page to the - * right could be any possible value. Assume that truncated - * attribute passes the qual. - */ - Assert(BTreeTupleIsPivot(tuple)); - cmpresult = 0; - if (subkey->sk_flags & SK_ROW_END) - break; - subkey++; - continue; - } - - datum = index_getattr(tuple, - subkey->sk_attno, - tupdesc, - &isNull); - - if (isNull) - { - if (forcenonrequired) - { - /* treating scan's keys as non-required */ - } - else if (subkey->sk_flags & SK_BT_NULLS_FIRST) - { - /* - * Since NULLs are sorted before non-NULLs, we know we have - * reached the lower limit of the range of values for this - * index attr. On a backward scan, we can stop if this qual - * is one of the "must match" subset. We can stop regardless - * of whether the qual is > or <, so long as it's required, - * because it's not possible for any future tuples to pass. On - * a forward scan, however, we must keep going, because we may - * have initially positioned to the start of the index. - * (_bt_advance_array_keys also relies on this behavior during - * forward scans.) - */ - if ((subkey->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD)) && - ScanDirectionIsBackward(dir)) - *continuescan = false; - } - else - { - /* - * Since NULLs are sorted after non-NULLs, we know we have - * reached the upper limit of the range of values for this - * index attr. On a forward scan, we can stop if this qual is - * one of the "must match" subset. We can stop regardless of - * whether the qual is > or <, so long as it's required, - * because it's not possible for any future tuples to pass. On - * a backward scan, however, we must keep going, because we - * may have initially positioned to the end of the index. - * (_bt_advance_array_keys also relies on this behavior during - * backward scans.) - */ - if ((subkey->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD)) && - ScanDirectionIsForward(dir)) - *continuescan = false; - } - - /* - * In any case, this indextuple doesn't match the qual. - */ - return false; - } - + /* When a NULL row member is compared, the row never matches */ if (subkey->sk_flags & SK_ISNULL) { /* @@ -3058,6 +2967,114 @@ _bt_check_rowcompare(ScanKey skey, IndexTuple tuple, int tupnatts, return false; } + if (subkey->sk_attno > tupnatts) + { + /* + * This attribute is truncated (must be high key). The value for + * this attribute in the first non-pivot tuple on the page to the + * right could be any possible value. Assume that truncated + * attribute passes the qual. + */ + Assert(BTreeTupleIsPivot(tuple)); + return true; + } + + datum = index_getattr(tuple, + subkey->sk_attno, + tupdesc, + &isNull); + + if (isNull) + { + int reqflags; + + if (forcenonrequired) + { + /* treating scan's keys as non-required */ + } + else if (subkey->sk_flags & SK_BT_NULLS_FIRST) + { + /* + * Since NULLs are sorted before non-NULLs, we know we have + * reached the lower limit of the range of values for this + * index attr. On a backward scan, we can stop if this qual + * is one of the "must match" subset. However, on a forwards + * scan, we must keep going, because we may have initially + * positioned to the start of the index. + * + * All required NULLS FIRST > row members can use NULL tuple + * values to end backwards scans, just like with other values. + * A qual "WHERE (a, b, c) > (9, 42, 'foo')" can terminate a + * backwards scan upon reaching the index's rightmost "a = 9" + * tuple whose "b" column contains a NULL (if not sooner). + * Since "b" is NULLS FIRST, we can treat its NULLs as "<" 42. + */ + reqflags = SK_BT_REQBKWD; + + /* + * When a most significant required NULLS FIRST < row compare + * member sees NULL tuple values during a backwards scan, it + * signals the end of matches for the whole row compare/scan. + * A qual "WHERE (a, b, c) < (9, 42, 'foo')" will terminate a + * backwards scan upon reaching the rightmost tuple whose "a" + * column has a NULL. The "a" NULL value is "<" 9, and yet + * our < row compare will still end the scan. (This isn't + * safe with later/lower-order row members. Notice that it + * can only happen with an "a" NULL some time after the scan + * completely stops needing to use its "b" and "c" members.) + */ + if (subkey == (ScanKey) DatumGetPointer(skey->sk_argument)) + reqflags |= SK_BT_REQFWD; /* safe, first row member */ + + if ((subkey->sk_flags & reqflags) && + ScanDirectionIsBackward(dir)) + *continuescan = false; + } + else + { + /* + * Since NULLs are sorted after non-NULLs, we know we have + * reached the upper limit of the range of values for this + * index attr. On a forward scan, we can stop if this qual is + * one of the "must match" subset. However, on a backward + * scan, we must keep going, because we may have initially + * positioned to the end of the index. + * + * All required NULLS LAST < row members can use NULL tuple + * values to end forwards scans, just like with other values. + * A qual "WHERE (a, b, c) < (9, 42, 'foo')" can terminate a + * forwards scan upon reaching the index's leftmost "a = 9" + * tuple whose "b" column contains a NULL (if not sooner). + * Since "b" is NULLS LAST, we can treat its NULLs as ">" 42. + */ + reqflags = SK_BT_REQFWD; + + /* + * When a most significant required NULLS LAST > row compare + * member sees NULL tuple values during a forwards scan, it + * signals the end of matches for the whole row compare/scan. + * A qual "WHERE (a, b, c) > (9, 42, 'foo')" will terminate a + * forwards scan upon reaching the leftmost tuple whose "a" + * column has a NULL. The "a" NULL value is ">" 9, and yet + * our > row compare will end the scan. (This isn't safe with + * later/lower-order row members. Notice that it can only + * happen with an "a" NULL some time after the scan completely + * stops needing to use its "b" and "c" members.) + */ + if (subkey == (ScanKey) DatumGetPointer(skey->sk_argument)) + reqflags |= SK_BT_REQBKWD; /* safe, first row member */ + + if ((subkey->sk_flags & reqflags) && + ScanDirectionIsForward(dir)) + *continuescan = false; + } + + /* + * In any case, this indextuple doesn't match the qual. + */ + return false; + } + /* Perform the test --- three-way comparison not bool operator */ cmpresult = DatumGetInt32(FunctionCall2Coll(&subkey->sk_func, subkey->sk_collation, diff --git a/src/test/regress/expected/btree_index.out b/src/test/regress/expected/btree_index.out index bfb1a286e..5aa538699 100644 --- a/src/test/regress/expected/btree_index.out +++ b/src/test/regress/expected/btree_index.out @@ -195,46 +195,116 @@ ORDER BY proname DESC, proargtypes DESC, pronamespace DESC LIMIT 1; (1 row) -- --- Add coverage for RowCompare quals whose rhs row has a NULL that ends scan +-- Add coverage for forwards scan RowCompare quals whose row arg has a NULL +-- that affects the initial positioning strategy -- explain (costs off) SELECT proname, proargtypes, pronamespace FROM pg_proc - WHERE proname = 'abs' AND (proname, proargtypes) < ('abs', NULL) + WHERE (proname, proargtypes) >= ('abs', NULL) AND proname <= 'abs' ORDER BY proname, proargtypes, pronamespace; - QUERY PLAN -------------------------------------------------------------------------------------------------------------- + QUERY PLAN +--------------------------------------------------------------------------------------------------------------- Index Only Scan using pg_proc_proname_args_nsp_index on pg_proc - Index Cond: ((ROW(proname, proargtypes) < ROW('abs'::name, NULL::oidvector)) AND (proname = 'abs'::name)) + Index Cond: ((ROW(proname, proargtypes) >= ROW('abs'::name, NULL::oidvector)) AND (proname <= 'abs'::name)) (2 rows) SELECT proname, proargtypes, pronamespace FROM pg_proc - WHERE proname = 'abs' AND (proname, proargtypes) < ('abs', NULL) + WHERE (proname, proargtypes) >= ('abs', NULL) AND proname <= 'abs' ORDER BY proname, proargtypes, pronamespace; proname | proargtypes | pronamespace ---------+-------------+-------------- (0 rows) -- --- Add coverage for backwards scan RowCompare quals whose rhs row has a NULL +-- Add coverage for forwards scan RowCompare quals whose row arg has a NULL -- that ends scan -- explain (costs off) SELECT proname, proargtypes, pronamespace FROM pg_proc - WHERE proname = 'abs' AND (proname, proargtypes) > ('abs', NULL) -ORDER BY proname DESC, proargtypes DESC, pronamespace DESC; - QUERY PLAN -------------------------------------------------------------------------------------------------------------- - Index Only Scan Backward using pg_proc_proname_args_nsp_index on pg_proc - Index Cond: ((ROW(proname, proargtypes) > ROW('abs'::name, NULL::oidvector)) AND (proname = 'abs'::name)) + WHERE proname >= 'abs' AND (proname, proargtypes) < ('abs', NULL) +ORDER BY proname, proargtypes, pronamespace; + QUERY PLAN +-------------------------------------------------------------------------------------------------------------- + Index Only Scan using pg_proc_proname_args_nsp_index on pg_proc + Index Cond: ((proname >= 'abs'::name) AND (ROW(proname, proargtypes) < ROW('abs'::name, NULL::oidvector))) (2 rows) SELECT proname, proargtypes, pronamespace FROM pg_proc - WHERE proname = 'abs' AND (proname, proargtypes) > ('abs', NULL) + WHERE proname >= 'abs' AND (proname, proargtypes) < ('abs', NULL) +ORDER BY proname, proargtypes, pronamespace; + proname | proargtypes | pronamespace +---------+-------------+-------------- +(0 rows) + +-- +-- Add coverage for backwards scan RowCompare quals whose row arg has a NULL +-- that affects the initial positioning strategy +-- +explain (costs off) +SELECT proname, proargtypes, pronamespace + FROM pg_proc + WHERE proname >= 'abs' AND (proname, proargtypes) <= ('abs', NULL) ORDER BY proname DESC, proargtypes DESC, pronamespace DESC; + QUERY PLAN +--------------------------------------------------------------------------------------------------------------- + Index Only Scan Backward using pg_proc_proname_args_nsp_index on pg_proc + Index Cond: ((proname >= 'abs'::name) AND (ROW(proname, proargtypes) <= ROW('abs'::name, NULL::oidvector))) +(2 rows) + +SELECT proname, proargtypes, pronamespace + FROM pg_proc + WHERE proname >= 'abs' AND (proname, proargtypes) <= ('abs', NULL) +ORDER BY proname DESC, proargtypes DESC, pronamespace DESC; + proname | proargtypes | pronamespace +---------+-------------+-------------- +(0 rows) + +-- +-- Add coverage for backwards scan RowCompare quals whose row arg has a NULL +-- that ends scan +-- +explain (costs off) +SELECT proname, proargtypes, pronamespace + FROM pg_proc + WHERE (proname, proargtypes) > ('abs', NULL) AND proname <= 'abs' +ORDER BY proname DESC, proargtypes DESC, pronamespace DESC; + QUERY PLAN +-------------------------------------------------------------------------------------------------------------- + Index Only Scan Backward using pg_proc_proname_args_nsp_index on pg_proc + Index Cond: ((ROW(proname, proargtypes) > ROW('abs'::name, NULL::oidvector)) AND (proname <= 'abs'::name)) +(2 rows) + +SELECT proname, proargtypes, pronamespace + FROM pg_proc + WHERE (proname, proargtypes) > ('abs', NULL) AND proname <= 'abs' +ORDER BY proname DESC, proargtypes DESC, pronamespace DESC; + proname | proargtypes | pronamespace +---------+-------------+-------------- +(0 rows) + +-- Add coverage for B-Tree preprocessing path that deals with making redundant +-- keys nonrequired (relies on current row compare preprocessing limitations) +explain (costs off) +SELECT proname, proargtypes, pronamespace + FROM pg_proc + WHERE proname = 'zzzzzz' AND (proname, proargtypes) > ('abs', NULL) + AND pronamespace IN (1, 2, 3) AND proargtypes IN ('26 23', '5077') +ORDER BY proname, proargtypes, pronamespace; + QUERY PLAN +-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- + Index Only Scan using pg_proc_proname_args_nsp_index on pg_proc + Index Cond: ((ROW(proname, proargtypes) > ROW('abs'::name, NULL::oidvector)) AND (proname = 'zzzzzz'::name) AND (proargtypes = ANY ('{"26 23",5077}'::oidvector[])) AND (pronamespace = ANY ('{1,2,3}'::oid[]))) +(2 rows) + +SELECT proname, proargtypes, pronamespace + FROM pg_proc + WHERE proname = 'zzzzzz' AND (proname, proargtypes) > ('abs', NULL) + AND pronamespace IN (1, 2, 3) AND proargtypes IN ('26 23', '5077') +ORDER BY proname, proargtypes, pronamespace; proname | proargtypes | pronamespace ---------+-------------+-------------- (0 rows) diff --git a/src/test/regress/sql/btree_index.sql b/src/test/regress/sql/btree_index.sql index 68c61dbc7..0d84e205f 100644 --- a/src/test/regress/sql/btree_index.sql +++ b/src/test/regress/sql/btree_index.sql @@ -143,34 +143,80 @@ SELECT proname, proargtypes, pronamespace ORDER BY proname DESC, proargtypes DESC, pronamespace DESC LIMIT 1; -- --- Add coverage for RowCompare quals whose rhs row has a NULL that ends scan +-- Add coverage for forwards scan RowCompare quals whose row arg has a NULL +-- that affects the initial positioning strategy -- explain (costs off) SELECT proname, proargtypes, pronamespace FROM pg_proc - WHERE proname = 'abs' AND (proname, proargtypes) < ('abs', NULL) + WHERE (proname, proargtypes) >= ('abs', NULL) AND proname <= 'abs' ORDER BY proname, proargtypes, pronamespace; SELECT proname, proargtypes, pronamespace FROM pg_proc - WHERE proname = 'abs' AND (proname, proargtypes) < ('abs', NULL) + WHERE (proname, proargtypes) >= ('abs', NULL) AND proname <= 'abs' ORDER BY proname, proargtypes, pronamespace; -- --- Add coverage for backwards scan RowCompare quals whose rhs row has a NULL +-- Add coverage for forwards scan RowCompare quals whose row arg has a NULL -- that ends scan -- explain (costs off) SELECT proname, proargtypes, pronamespace FROM pg_proc - WHERE proname = 'abs' AND (proname, proargtypes) > ('abs', NULL) + WHERE proname >= 'abs' AND (proname, proargtypes) < ('abs', NULL) +ORDER BY proname, proargtypes, pronamespace; + +SELECT proname, proargtypes, pronamespace + FROM pg_proc + WHERE proname >= 'abs' AND (proname, proargtypes) < ('abs', NULL) +ORDER BY proname, proargtypes, pronamespace; + +-- +-- Add coverage for backwards scan RowCompare quals whose row arg has a NULL +-- that affects the initial positioning strategy +-- +explain (costs off) +SELECT proname, proargtypes, pronamespace + FROM pg_proc + WHERE proname >= 'abs' AND (proname, proargtypes) <= ('abs', NULL) ORDER BY proname DESC, proargtypes DESC, pronamespace DESC; SELECT proname, proargtypes, pronamespace FROM pg_proc - WHERE proname = 'abs' AND (proname, proargtypes) > ('abs', NULL) + WHERE proname >= 'abs' AND (proname, proargtypes) <= ('abs', NULL) ORDER BY proname DESC, proargtypes DESC, pronamespace DESC; +-- +-- Add coverage for backwards scan RowCompare quals whose row arg has a NULL +-- that ends scan +-- +explain (costs off) +SELECT proname, proargtypes, pronamespace + FROM pg_proc + WHERE (proname, proargtypes) > ('abs', NULL) AND proname <= 'abs' +ORDER BY proname DESC, proargtypes DESC, pronamespace DESC; + +SELECT proname, proargtypes, pronamespace + FROM pg_proc + WHERE (proname, proargtypes) > ('abs', NULL) AND proname <= 'abs' +ORDER BY proname DESC, proargtypes DESC, pronamespace DESC; + +-- Add coverage for B-Tree preprocessing path that deals with making redundant +-- keys nonrequired (relies on current row compare preprocessing limitations) +explain (costs off) +SELECT proname, proargtypes, pronamespace + FROM pg_proc + WHERE proname = 'zzzzzz' AND (proname, proargtypes) > ('abs', NULL) + AND pronamespace IN (1, 2, 3) AND proargtypes IN ('26 23', '5077') +ORDER BY proname, proargtypes, pronamespace; + +SELECT proname, proargtypes, pronamespace + FROM pg_proc + WHERE proname = 'zzzzzz' AND (proname, proargtypes) > ('abs', NULL) + AND pronamespace IN (1, 2, 3) AND proargtypes IN ('26 23', '5077') +ORDER BY proname, proargtypes, pronamespace; + -- -- Add coverage for recheck of > key following array advancement on previous -- (left sibling) page that used a high key whose attribute value corresponding -- 2.50.0