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[PATCH 2/8] Move IS [NOT] NULL handling from BRIN support functions 2+ messages / 2 participants [nested] [flat]
* [PATCH 2/8] Move IS [NOT] NULL handling from BRIN support functions @ 2020-09-17 15:26 Tomas Vondra <[email protected]> 0 siblings, 0 replies; 2+ messages in thread From: Tomas Vondra @ 2020-09-17 15:26 UTC (permalink / raw) The handling of IS [NOT] NULL clauses is independent of an opclass, and most of the code was exactly the same in both minmax and inclusion. So instead move the code from support procedures to the AM methods etc. This simplifies the code quite a bit - especially the support procedures quite a bit, as they don't need to care about NULL values and flags at all. It also means the IS [NOT] NULL clauses can be evaluated without invoking the support procedure at all. Author: Tomas Vondra <[email protected]> Author: Nikita Glukhov <[email protected]> Reviewed-by: Alvaro Herrera <[email protected]> Reviewed-by: Mark Dilger <[email protected]> Reviewed-by: Alexander Korotkov <[email protected]> Reviewed-by: Masahiko Sawada <[email protected]> Reviewed-by: John Naylor <[email protected]> Discussion: https://postgr.es/m/[email protected] --- src/backend/access/brin/brin.c | 293 +++++++++++++++++------ src/backend/access/brin/brin_inclusion.c | 106 +------- src/backend/access/brin/brin_minmax.c | 103 +------- src/include/access/brin_internal.h | 3 + 4 files changed, 239 insertions(+), 266 deletions(-) diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c index 8a1a9da78f..55851376d8 100644 --- a/src/backend/access/brin/brin.c +++ b/src/backend/access/brin/brin.c @@ -35,6 +35,7 @@ #include "storage/freespace.h" #include "utils/acl.h" #include "utils/builtins.h" +#include "utils/datum.h" #include "utils/index_selfuncs.h" #include "utils/memutils.h" #include "utils/rel.h" @@ -77,7 +78,9 @@ static void form_and_insert_tuple(BrinBuildState *state); static void union_tuples(BrinDesc *bdesc, BrinMemTuple *a, BrinTuple *b); static void brin_vacuum_scan(Relation idxrel, BufferAccessStrategy strategy); - +static bool add_values_to_range(Relation idxRel, BrinDesc *bdesc, + BrinMemTuple *dtup, Datum *values, bool *nulls); +static bool check_null_keys(BrinValues *bval, ScanKey *nullkeys, int nnullkeys); /* * BRIN handler function: return IndexAmRoutine with access method parameters @@ -178,7 +181,6 @@ brininsert(Relation idxRel, Datum *values, bool *nulls, OffsetNumber off; BrinTuple *brtup; BrinMemTuple *dtup; - int keyno; CHECK_FOR_INTERRUPTS(); @@ -242,31 +244,7 @@ brininsert(Relation idxRel, Datum *values, bool *nulls, dtup = brin_deform_tuple(bdesc, brtup, NULL); - /* - * Compare the key values of the new tuple to the stored index values; - * our deformed tuple will get updated if the new tuple doesn't fit - * the original range (note this means we can't break out of the loop - * early). Make a note of whether this happens, so that we know to - * insert the modified tuple later. - */ - for (keyno = 0; keyno < bdesc->bd_tupdesc->natts; keyno++) - { - Datum result; - BrinValues *bval; - FmgrInfo *addValue; - - bval = &dtup->bt_columns[keyno]; - addValue = index_getprocinfo(idxRel, keyno + 1, - BRIN_PROCNUM_ADDVALUE); - result = FunctionCall4Coll(addValue, - idxRel->rd_indcollation[keyno], - PointerGetDatum(bdesc), - PointerGetDatum(bval), - values[keyno], - nulls[keyno]); - /* if that returned true, we need to insert the updated tuple */ - need_insert |= DatumGetBool(result); - } + need_insert = add_values_to_range(idxRel, bdesc, dtup, values, nulls); if (!need_insert) { @@ -389,8 +367,10 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm) BrinMemTuple *dtup; BrinTuple *btup = NULL; Size btupsz = 0; - ScanKey **keys; - int *nkeys; + ScanKey **keys, + **nullkeys; + int *nkeys, + *nnullkeys; int keyno; opaque = (BrinOpaque *) scan->opaque; @@ -415,10 +395,13 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm) /* * Make room for per-attribute lists of scan keys that we'll pass to the - * consistent support procedure. + * consistent support procedure. We keep null and regular keys separate, + * so that we can easily pass regular keys to the consistent function. */ keys = palloc0(sizeof(ScanKey *) * bdesc->bd_tupdesc->natts); + nullkeys = palloc0(sizeof(ScanKey *) * bdesc->bd_tupdesc->natts); nkeys = palloc0(sizeof(int) * bdesc->bd_tupdesc->natts); + nnullkeys = palloc0(sizeof(int) * bdesc->bd_tupdesc->natts); /* * Preprocess the scan keys - split them into per-attribute arrays. @@ -439,23 +422,24 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm) TupleDescAttr(bdesc->bd_tupdesc, keyattno - 1)->attcollation)); - /* First time we see this index attribute, so init as needed. */ - if (!keys[keyattno-1]) + /* + * First time we see this index attribute, so init as needed. + * + * This is a bit of an overkill - we don't know how many scan + * keys are there for a given attribute, so we simply allocate + * the largest number possible (as if all scan keys belonged to + * the same attribute). This may waste a bit of memory, but we + * only expect small number of scan keys in general, so this + * should be negligible, and it's probably cheaper than having + * to repalloc repeatedly. + */ + if (consistentFn[keyattno - 1].fn_oid == InvalidOid) { FmgrInfo *tmp; - /* - * This is a bit of an overkill - we don't know how many - * scan keys are there for this attribute, so we simply - * allocate the largest number possible. This may waste - * a bit of memory, but we only expect small number of - * scan keys in general, so this should be negligible, - * and it's cheaper than having to repalloc repeatedly. - */ - keys[keyattno - 1] = palloc0(sizeof(ScanKey) * scan->numberOfKeys); - - /* First time this column, so look up consistent function */ - Assert(consistentFn[keyattno - 1].fn_oid == InvalidOid); + /* No key/null arrays for this attribute. */ + Assert((keys[keyattno - 1] == NULL) && (nkeys[keyattno - 1] == 0)); + Assert((nullkeys[keyattno - 1] == NULL) && (nnullkeys[keyattno - 1] == 0)); tmp = index_getprocinfo(idxRel, keyattno, BRIN_PROCNUM_CONSISTENT); @@ -463,9 +447,23 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm) CurrentMemoryContext); } - /* Add key to the per-attribute array. */ - keys[keyattno - 1][nkeys[keyattno - 1]] = key; - nkeys[keyattno - 1]++; + /* Add key to the proper per-attribute array. */ + if (key->sk_flags & SK_ISNULL) + { + if (!nullkeys[keyattno - 1]) + nullkeys[keyattno - 1] = palloc0(sizeof(ScanKey) * scan->numberOfKeys); + + nullkeys[keyattno - 1][nnullkeys[keyattno - 1]] = key; + nnullkeys[keyattno - 1]++; + } + else + { + if (!keys[keyattno - 1]) + keys[keyattno - 1] = palloc0(sizeof(ScanKey) * scan->numberOfKeys); + + keys[keyattno - 1][nkeys[keyattno - 1]] = key; + nkeys[keyattno - 1]++; + } } /* allocate an initial in-memory tuple, out of the per-range memcxt */ @@ -543,15 +541,57 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm) BrinValues *bval; Datum add; - /* skip attributes without any san keys */ - if (nkeys[attno - 1] == 0) + /* + * skip attributes without any scan keys (both regular + * and IS [NOT] NULL) + */ + if (nkeys[attno - 1] == 0 && nnullkeys[attno - 1] == 0) continue; bval = &dtup->bt_columns[attno - 1]; + /* + * First check if there are any IS [NOT] NULL scan keys, + * and if we're violating them. In that case we can + * terminate early, without invoking the support function. + * + * As there may be more keys, we can only detemine mismatch + * within this loop. + */ + if (bdesc->bd_info[attno - 1]->oi_regular_nulls && + !check_null_keys(bval, nullkeys[attno - 1], + nnullkeys[attno - 1])) + { + /* + * If any of the IS [NOT] NULL keys failed, the page + * range as a whole can't pass. So terminate the loop. + */ + addrange = false; + break; + } + + /* + * So either there are no IS [NOT] NULL keys, or all passed. + * If there are no regular scan keys, we're done - the page + * range matches. If there are regular keys, but the page + * range is marked as 'all nulls' it can't possibly pass + * (we're assuming the operators are strict). + */ + + /* No regular scan keys - page range as a whole passes. */ + if (!nkeys[attno - 1]) + continue; + Assert((nkeys[attno - 1] > 0) && (nkeys[attno - 1] <= scan->numberOfKeys)); + /* If it is all nulls, it cannot possibly be consistent. */ + if (bval->bv_allnulls) + { + addrange = false; + break; + } + /* * Check whether the scan key is consistent with the page * range values; if so, have the pages in the range added @@ -694,7 +734,6 @@ brinbuildCallback(Relation index, { BrinBuildState *state = (BrinBuildState *) brstate; BlockNumber thisblock; - int i; thisblock = ItemPointerGetBlockNumber(tid); @@ -723,25 +762,8 @@ brinbuildCallback(Relation index, } /* Accumulate the current tuple into the running state */ - for (i = 0; i < state->bs_bdesc->bd_tupdesc->natts; i++) - { - FmgrInfo *addValue; - BrinValues *col; - Form_pg_attribute attr = TupleDescAttr(state->bs_bdesc->bd_tupdesc, i); - - col = &state->bs_dtuple->bt_columns[i]; - addValue = index_getprocinfo(index, i + 1, - BRIN_PROCNUM_ADDVALUE); - - /* - * Update dtuple state, if and as necessary. - */ - FunctionCall4Coll(addValue, - attr->attcollation, - PointerGetDatum(state->bs_bdesc), - PointerGetDatum(col), - values[i], isnull[i]); - } + (void) add_values_to_range(index, state->bs_bdesc, state->bs_dtuple, + values, isnull); } /* @@ -1520,6 +1542,39 @@ union_tuples(BrinDesc *bdesc, BrinMemTuple *a, BrinTuple *b) FmgrInfo *unionFn; BrinValues *col_a = &a->bt_columns[keyno]; BrinValues *col_b = &db->bt_columns[keyno]; + BrinOpcInfo *opcinfo = bdesc->bd_info[keyno]; + + if (opcinfo->oi_regular_nulls) + { + /* Adjust "hasnulls". */ + if (!col_a->bv_hasnulls && col_b->bv_hasnulls) + col_a->bv_hasnulls = true; + + /* If there are no values in B, there's nothing left to do. */ + if (col_b->bv_allnulls) + continue; + + /* + * Adjust "allnulls". If A doesn't have values, just copy the + * values from B into A, and we're done. We cannot run the + * operators in this case, because values in A might contain + * garbage. Note we already established that B contains values. + */ + if (col_a->bv_allnulls) + { + int i; + + col_a->bv_allnulls = false; + + for (i = 0; i < opcinfo->oi_nstored; i++) + col_a->bv_values[i] = + datumCopy(col_b->bv_values[i], + opcinfo->oi_typcache[i]->typbyval, + opcinfo->oi_typcache[i]->typlen); + + continue; + } + } unionFn = index_getprocinfo(bdesc->bd_index, keyno + 1, BRIN_PROCNUM_UNION); @@ -1573,3 +1628,103 @@ brin_vacuum_scan(Relation idxrel, BufferAccessStrategy strategy) */ FreeSpaceMapVacuum(idxrel); } + +static bool +add_values_to_range(Relation idxRel, BrinDesc *bdesc, BrinMemTuple *dtup, + Datum *values, bool *nulls) +{ + int keyno; + bool modified = false; + + /* + * Compare the key values of the new tuple to the stored index values; + * our deformed tuple will get updated if the new tuple doesn't fit + * the original range (note this means we can't break out of the loop + * early). Make a note of whether this happens, so that we know to + * insert the modified tuple later. + */ + for (keyno = 0; keyno < bdesc->bd_tupdesc->natts; keyno++) + { + Datum result; + BrinValues *bval; + FmgrInfo *addValue; + + bval = &dtup->bt_columns[keyno]; + + if (bdesc->bd_info[keyno]->oi_regular_nulls && nulls[keyno]) + { + /* + * If the new value is null, we record that we saw it if it's + * the first one; otherwise, there's nothing to do. + */ + if (!bval->bv_hasnulls) + { + bval->bv_hasnulls = true; + modified = true; + } + + continue; + } + + addValue = index_getprocinfo(idxRel, keyno + 1, + BRIN_PROCNUM_ADDVALUE); + result = FunctionCall4Coll(addValue, + idxRel->rd_indcollation[keyno], + PointerGetDatum(bdesc), + PointerGetDatum(bval), + values[keyno], + nulls[keyno]); + /* if that returned true, we need to insert the updated tuple */ + modified |= DatumGetBool(result); + } + + return modified; +} + +static bool +check_null_keys(BrinValues *bval, ScanKey *nullkeys, int nnullkeys) +{ + int keyno; + + /* + * First check if there are any IS [NOT] NULL scan keys, and if we're + * violating them. + */ + for (keyno = 0; keyno < nnullkeys; keyno++) + { + ScanKey key = nullkeys[keyno]; + + Assert(key->sk_attno == bval->bv_attno); + + /* Handle only IS NULL/IS NOT NULL tests */ + if (!(key->sk_flags & SK_ISNULL)) + continue; + + if (key->sk_flags & SK_SEARCHNULL) + { + /* IS NULL scan key, but range has no NULLs */ + if (!bval->bv_allnulls && !bval->bv_hasnulls) + return false; + } + else if (key->sk_flags & SK_SEARCHNOTNULL) + { + /* + * For IS NOT NULL, we can only skip ranges that are known to + * have only nulls. + */ + if (bval->bv_allnulls) + return false; + } + else + { + /* + * Neither IS NULL nor IS NOT NULL was used; assume all indexable + * operators are strict and thus return false with NULL value in + * the scan key. + */ + return false; + } + } + + return true; +} diff --git a/src/backend/access/brin/brin_inclusion.c b/src/backend/access/brin/brin_inclusion.c index 215bc794d3..f4730be3b9 100644 --- a/src/backend/access/brin/brin_inclusion.c +++ b/src/backend/access/brin/brin_inclusion.c @@ -110,6 +110,7 @@ brin_inclusion_opcinfo(PG_FUNCTION_ARGS) */ result = palloc0(MAXALIGN(SizeofBrinOpcInfo(3)) + sizeof(InclusionOpaque)); result->oi_nstored = 3; + result->oi_regular_nulls = true; result->oi_opaque = (InclusionOpaque *) MAXALIGN((char *) result + SizeofBrinOpcInfo(3)); @@ -141,7 +142,7 @@ brin_inclusion_add_value(PG_FUNCTION_ARGS) BrinDesc *bdesc = (BrinDesc *) PG_GETARG_POINTER(0); BrinValues *column = (BrinValues *) PG_GETARG_POINTER(1); Datum newval = PG_GETARG_DATUM(2); - bool isnull = PG_GETARG_BOOL(3); + bool isnull PG_USED_FOR_ASSERTS_ONLY = PG_GETARG_BOOL(3); Oid colloid = PG_GET_COLLATION(); FmgrInfo *finfo; Datum result; @@ -149,18 +150,7 @@ brin_inclusion_add_value(PG_FUNCTION_ARGS) AttrNumber attno; Form_pg_attribute attr; - /* - * If the new value is null, we record that we saw it if it's the first - * one; otherwise, there's nothing to do. - */ - if (isnull) - { - if (column->bv_hasnulls) - PG_RETURN_BOOL(false); - - column->bv_hasnulls = true; - PG_RETURN_BOOL(true); - } + Assert(!isnull); attno = column->bv_attno; attr = TupleDescAttr(bdesc->bd_tupdesc, attno - 1); @@ -264,63 +254,6 @@ brin_inclusion_consistent(PG_FUNCTION_ARGS) int nkeys = PG_GETARG_INT32(3); Oid colloid = PG_GET_COLLATION(); int keyno; - bool regular_keys = false; - - /* - * First check if there are any IS NULL scan keys, and if we're - * violating them. In that case we can terminate early, without - * inspecting the ranges. - */ - for (keyno = 0; keyno < nkeys; keyno++) - { - ScanKey key = keys[keyno]; - - Assert(key->sk_attno == column->bv_attno); - - /* handle IS NULL/IS NOT NULL tests */ - if (key->sk_flags & SK_ISNULL) - { - if (key->sk_flags & SK_SEARCHNULL) - { - if (column->bv_allnulls || column->bv_hasnulls) - continue; /* this key is fine, continue */ - - PG_RETURN_BOOL(false); - } - - /* - * For IS NOT NULL, we can only skip ranges that are known to have - * only nulls. - */ - if (key->sk_flags & SK_SEARCHNOTNULL) - { - if (column->bv_allnulls) - PG_RETURN_BOOL(false); - - continue; - } - - /* - * Neither IS NULL nor IS NOT NULL was used; assume all indexable - * operators are strict and return false. - */ - PG_RETURN_BOOL(false); - } - else - /* note we have regular (non-NULL) scan keys */ - regular_keys = true; - } - - /* - * If the page range is all nulls, it cannot possibly be consistent if - * there are some regular scan keys. - */ - if (column->bv_allnulls && regular_keys) - PG_RETURN_BOOL(false); - - /* If there are no regular keys, the page range is considered consistent. */ - if (!regular_keys) - PG_RETURN_BOOL(true); /* It has to be checked, if it contains elements that are not mergeable. */ if (DatumGetBool(column->bv_values[INCLUSION_UNMERGEABLE])) @@ -331,9 +264,8 @@ brin_inclusion_consistent(PG_FUNCTION_ARGS) { ScanKey key = keys[keyno]; - /* ignore IS NULL/IS NOT NULL tests handled above */ - if (key->sk_flags & SK_ISNULL) - continue; + /* NULL keys are handled and filtered-out in bringetbitmap */ + Assert(!(key->sk_flags & SK_ISNULL)); /* * When there are multiple scan keys, failure to meet the @@ -572,37 +504,11 @@ brin_inclusion_union(PG_FUNCTION_ARGS) Datum result; Assert(col_a->bv_attno == col_b->bv_attno); - - /* Adjust "hasnulls". */ - if (!col_a->bv_hasnulls && col_b->bv_hasnulls) - col_a->bv_hasnulls = true; - - /* If there are no values in B, there's nothing left to do. */ - if (col_b->bv_allnulls) - PG_RETURN_VOID(); + Assert(!col_a->bv_allnulls && !col_b->bv_allnulls); attno = col_a->bv_attno; attr = TupleDescAttr(bdesc->bd_tupdesc, attno - 1); - /* - * Adjust "allnulls". If A doesn't have values, just copy the values from - * B into A, and we're done. We cannot run the operators in this case, - * because values in A might contain garbage. Note we already established - * that B contains values. - */ - if (col_a->bv_allnulls) - { - col_a->bv_allnulls = false; - col_a->bv_values[INCLUSION_UNION] = - datumCopy(col_b->bv_values[INCLUSION_UNION], - attr->attbyval, attr->attlen); - col_a->bv_values[INCLUSION_UNMERGEABLE] = - col_b->bv_values[INCLUSION_UNMERGEABLE]; - col_a->bv_values[INCLUSION_CONTAINS_EMPTY] = - col_b->bv_values[INCLUSION_CONTAINS_EMPTY]; - PG_RETURN_VOID(); - } - /* If B includes empty elements, mark A similarly, if needed. */ if (!DatumGetBool(col_a->bv_values[INCLUSION_CONTAINS_EMPTY]) && DatumGetBool(col_b->bv_values[INCLUSION_CONTAINS_EMPTY])) diff --git a/src/backend/access/brin/brin_minmax.c b/src/backend/access/brin/brin_minmax.c index 12878ff3a0..6c8852d404 100644 --- a/src/backend/access/brin/brin_minmax.c +++ b/src/backend/access/brin/brin_minmax.c @@ -48,6 +48,7 @@ brin_minmax_opcinfo(PG_FUNCTION_ARGS) result = palloc0(MAXALIGN(SizeofBrinOpcInfo(2)) + sizeof(MinmaxOpaque)); result->oi_nstored = 2; + result->oi_regular_nulls = true; result->oi_opaque = (MinmaxOpaque *) MAXALIGN((char *) result + SizeofBrinOpcInfo(2)); result->oi_typcache[0] = result->oi_typcache[1] = @@ -69,7 +70,7 @@ brin_minmax_add_value(PG_FUNCTION_ARGS) BrinDesc *bdesc = (BrinDesc *) PG_GETARG_POINTER(0); BrinValues *column = (BrinValues *) PG_GETARG_POINTER(1); Datum newval = PG_GETARG_DATUM(2); - bool isnull = PG_GETARG_DATUM(3); + bool isnull PG_USED_FOR_ASSERTS_ONLY = PG_GETARG_DATUM(3); Oid colloid = PG_GET_COLLATION(); FmgrInfo *cmpFn; Datum compar; @@ -77,18 +78,7 @@ brin_minmax_add_value(PG_FUNCTION_ARGS) Form_pg_attribute attr; AttrNumber attno; - /* - * If the new value is null, we record that we saw it if it's the first - * one; otherwise, there's nothing to do. - */ - if (isnull) - { - if (column->bv_hasnulls) - PG_RETURN_BOOL(false); - - column->bv_hasnulls = true; - PG_RETURN_BOOL(true); - } + Assert(!isnull); attno = column->bv_attno; attr = TupleDescAttr(bdesc->bd_tupdesc, attno - 1); @@ -152,72 +142,14 @@ brin_minmax_consistent(PG_FUNCTION_ARGS) int nkeys = PG_GETARG_INT32(3); Oid colloid = PG_GET_COLLATION(); int keyno; - bool regular_keys = false; - - /* - * First check if there are any IS NULL scan keys, and if we're - * violating them. In that case we can terminate early, without - * inspecting the ranges. - */ - for (keyno = 0; keyno < nkeys; keyno++) - { - ScanKey key = keys[keyno]; - - Assert(key->sk_attno == column->bv_attno); - - /* handle IS NULL/IS NOT NULL tests */ - if (key->sk_flags & SK_ISNULL) - { - if (key->sk_flags & SK_SEARCHNULL) - { - if (column->bv_allnulls || column->bv_hasnulls) - continue; /* this key is fine, continue */ - - PG_RETURN_BOOL(false); - } - - /* - * For IS NOT NULL, we can only skip ranges that are known to have - * only nulls. - */ - if (key->sk_flags & SK_SEARCHNOTNULL) - { - if (column->bv_allnulls) - PG_RETURN_BOOL(false); - - continue; - } - - /* - * Neither IS NULL nor IS NOT NULL was used; assume all indexable - * operators are strict and return false. - */ - PG_RETURN_BOOL(false); - } - else - /* note we have regular (non-NULL) scan keys */ - regular_keys = true; - } - - /* - * If the page range is all nulls, it cannot possibly be consistent if - * there are some regular scan keys. - */ - if (column->bv_allnulls && regular_keys) - PG_RETURN_BOOL(false); - - /* If there are no regular keys, the page range is considered consistent. */ - if (!regular_keys) - PG_RETURN_BOOL(true); /* Check that the range is consistent with all scan keys. */ for (keyno = 0; keyno < nkeys; keyno++) { ScanKey key = keys[keyno]; - /* ignore IS NULL/IS NOT NULL tests handled above */ - if (key->sk_flags & SK_ISNULL) - continue; + /* NULL keys are handled and filtered-out in bringetbitmap */ + Assert(!(key->sk_flags & SK_ISNULL)); /* * When there are multiple scan keys, failure to meet the @@ -308,34 +240,11 @@ brin_minmax_union(PG_FUNCTION_ARGS) bool needsadj; Assert(col_a->bv_attno == col_b->bv_attno); - - /* Adjust "hasnulls" */ - if (!col_a->bv_hasnulls && col_b->bv_hasnulls) - col_a->bv_hasnulls = true; - - /* If there are no values in B, there's nothing left to do */ - if (col_b->bv_allnulls) - PG_RETURN_VOID(); + Assert(!col_a->bv_allnulls && !col_b->bv_allnulls); attno = col_a->bv_attno; attr = TupleDescAttr(bdesc->bd_tupdesc, attno - 1); - /* - * Adjust "allnulls". If A doesn't have values, just copy the values from - * B into A, and we're done. We cannot run the operators in this case, - * because values in A might contain garbage. Note we already established - * that B contains values. - */ - if (col_a->bv_allnulls) - { - col_a->bv_allnulls = false; - col_a->bv_values[0] = datumCopy(col_b->bv_values[0], - attr->attbyval, attr->attlen); - col_a->bv_values[1] = datumCopy(col_b->bv_values[1], - attr->attbyval, attr->attlen); - PG_RETURN_VOID(); - } - /* Adjust minimum, if B's min is less than A's min */ finfo = minmax_get_strategy_procinfo(bdesc, attno, attr->atttypid, BTLessStrategyNumber); diff --git a/src/include/access/brin_internal.h b/src/include/access/brin_internal.h index 85c612e490..7b79a52536 100644 --- a/src/include/access/brin_internal.h +++ b/src/include/access/brin_internal.h @@ -27,6 +27,9 @@ typedef struct BrinOpcInfo /* Number of columns stored in an index column of this opclass */ uint16 oi_nstored; + /* Regular processing of NULLs in BrinValues? */ + bool oi_regular_nulls; + /* Opaque pointer for the opclass' private use */ void *oi_opaque; -- 2.26.2 --------------CF71AF65F7C337C37C24B045 Content-Type: text/x-patch; charset=UTF-8; name="0003-Optimize-allocations-in-bringetbitmap-20210112.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename*0="0003-Optimize-allocations-in-bringetbitmap-20210112.patch" ^ permalink raw reply [nested|flat] 2+ messages in thread
* [PATCH v5 5/7] Row pattern recognition patch (docs). @ 2023-09-02 06:32 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 2+ messages in thread From: Tatsuo Ishii @ 2023-09-02 06:32 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 52 ++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 +++++++++++++++++++++++-- 3 files changed, 142 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..eda3612822 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,58 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used with row pattern common syntax to + perform row pattern recognition in a query. Row pattern common syntax + includes two sub clauses. <literal>DEFINE</literal> defines definition + variables along with an expression. The expression must be a logical + expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. Moreover if the expression comprises a column + reference, it must be the argument of <function>rpr</function>. An example + of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns price column in the previous + row if it's called in a context of row pattern recognition. So in the + second line means the definition variable "UP" is <literal>TRUE</literal> + when price column in the current row is greater than the price column in + the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a + sequence of rows found, rpr returns the column at the starting row. + Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, max(price) OVER w FROM stock + WINDOW w AS ( + PARTITION BY company + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 7a0d4b9134..b7bfc9271e 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21772,6 +21772,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21811,6 +21812,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0ee0cc7e64..8d3becd57a 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1074,6 +1074,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_Sep__2_15_52_35_2023_273)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v5-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2023-09-02 06:32 UTC | newest] Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2020-09-17 15:26 [PATCH 2/8] Move IS [NOT] NULL handling from BRIN support functions Tomas Vondra <[email protected]> 2023-09-02 06:32 [PATCH v5 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]>
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