-<!-- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.174 2008/09/15 18:43:41 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.175 2008/09/19 19:03:40 tgl Exp $ -->
<!--
Documentation of the system catalogs, directed toward PostgreSQL developers
-->
A list of the frequencies of the most common values or elements,
i.e., number of occurrences of each divided by total number of rows.
(NULL when <structfield>most_common_vals</structfield> is.)
+ For some datatypes such as <type>tsvector</>, it can also store some
+ additional information, making it longer than the
+ <structfield>most_common_vals</> array.
</entry>
</row>
#
# Copyright (c) 2006-2008, PostgreSQL Global Development Group
#
-# $PostgreSQL: pgsql/src/backend/tsearch/Makefile,v 1.7 2008/07/14 00:51:45 tgl Exp $
+# $PostgreSQL: pgsql/src/backend/tsearch/Makefile,v 1.8 2008/09/19 19:03:40 tgl Exp $
#
#-------------------------------------------------------------------------
subdir = src/backend/tsearch
OBJS = ts_locale.o ts_parse.o wparser.o wparser_def.o dict.o \
dict_simple.o dict_synonym.o dict_thesaurus.o \
dict_ispell.o regis.o spell.o \
- to_tsany.o ts_typanalyze.o ts_utils.o
+ to_tsany.o ts_selfuncs.o ts_typanalyze.o ts_utils.o
include $(top_srcdir)/src/backend/common.mk
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * ts_selfuncs.c
+ * Selectivity estimation functions for text search operators.
+ *
+ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ * $PostgreSQL: pgsql/src/backend/tsearch/ts_selfuncs.c,v 1.1 2008/09/19 19:03:40 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "catalog/pg_statistic.h"
+#include "catalog/pg_type.h"
+#include "miscadmin.h"
+#include "nodes/nodes.h"
+#include "tsearch/ts_type.h"
+#include "utils/lsyscache.h"
+#include "utils/selfuncs.h"
+#include "utils/syscache.h"
+
+
+/*
+ * The default text search selectivity is chosen to be small enough to
+ * encourage indexscans for typical table densities. See selfuncs.h and
+ * DEFAULT_EQ_SEL for details.
+ */
+#define DEFAULT_TS_MATCH_SEL 0.005
+
+/* lookup table type for binary searching through MCELEMs */
+typedef struct
+{
+ text *element;
+ float4 frequency;
+} TextFreq;
+
+/* type of keys for bsearch'ing through an array of TextFreqs */
+typedef struct
+{
+ char *lexeme;
+ int length;
+} LexemeKey;
+
+static Selectivity tsquerysel(VariableStatData *vardata, Datum constval);
+static Selectivity mcelem_tsquery_selec(TSQuery query,
+ Datum *mcelem, int nmcelem,
+ float4 *numbers, int nnumbers);
+static Selectivity tsquery_opr_selec(QueryItem *item, char *operand,
+ TextFreq *lookup, int length, float4 minfreq);
+static int compare_lexeme_textfreq(const void *e1, const void *e2);
+
+
+/*
+ * tsmatchsel -- Selectivity of "@@"
+ *
+ * restriction selectivity function for tsvector @@ tsquery and
+ * tsquery @@ tsvector
+ */
+Datum
+tsmatchsel(PG_FUNCTION_ARGS)
+{
+ PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
+#ifdef NOT_USED
+ Oid operator = PG_GETARG_OID(1);
+#endif
+ List *args = (List *) PG_GETARG_POINTER(2);
+ int varRelid = PG_GETARG_INT32(3);
+ VariableStatData vardata;
+ Node *other;
+ bool varonleft;
+ Selectivity selec;
+
+ /*
+ * If expression is not variable = something or something = variable, then
+ * punt and return a default estimate.
+ */
+ if (!get_restriction_variable(root, args, varRelid,
+ &vardata, &other, &varonleft))
+ PG_RETURN_FLOAT8(DEFAULT_TS_MATCH_SEL);
+
+ /*
+ * Can't do anything useful if the something is not a constant, either.
+ */
+ if (!IsA(other, Const))
+ {
+ ReleaseVariableStats(vardata);
+ PG_RETURN_FLOAT8(DEFAULT_TS_MATCH_SEL);
+ }
+
+ /*
+ * The "@@" operator is strict, so we can cope with NULL right away
+ */
+ if (((Const *) other)->constisnull)
+ {
+ ReleaseVariableStats(vardata);
+ PG_RETURN_FLOAT8(0.0);
+ }
+
+ /*
+ * OK, there's a Var and a Const we're dealing with here. We need the Var
+ * to be a TSVector (or else we don't have any useful statistic for it).
+ * We have to check this because the Var might be the TSQuery not the
+ * TSVector.
+ */
+ if (vardata.vartype == TSVECTOROID)
+ {
+ /* tsvector @@ tsquery or the other way around */
+ Assert(((Const *) other)->consttype == TSQUERYOID);
+
+ selec = tsquerysel(&vardata, ((Const *) other)->constvalue);
+ }
+ else
+ {
+ /* The Var is something we don't have useful statistics for */
+ selec = DEFAULT_TS_MATCH_SEL;
+ }
+
+ ReleaseVariableStats(vardata);
+
+ CLAMP_PROBABILITY(selec);
+
+ PG_RETURN_FLOAT8((float8) selec);
+}
+
+
+/*
+ * tsmatchjoinsel -- join selectivity of "@@"
+ *
+ * join selectivity function for tsvector @@ tsquery and tsquery @@ tsvector
+ */
+Datum
+tsmatchjoinsel(PG_FUNCTION_ARGS)
+{
+ /* for the moment we just punt */
+ PG_RETURN_FLOAT8(DEFAULT_TS_MATCH_SEL);
+}
+
+
+/*
+ * @@ selectivity for tsvector var vs tsquery constant
+ */
+static Selectivity
+tsquerysel(VariableStatData *vardata, Datum constval)
+{
+ Selectivity selec;
+
+ if (HeapTupleIsValid(vardata->statsTuple))
+ {
+ TSQuery query;
+ Form_pg_statistic stats;
+ Datum *values;
+ int nvalues;
+ float4 *numbers;
+ int nnumbers;
+
+ /* The caller made sure the const is a TSQuery, so get it now */
+ query = DatumGetTSQuery(constval);
+
+ stats = (Form_pg_statistic) GETSTRUCT(vardata->statsTuple);
+
+ /* MCELEM will be an array of TEXT elements for a tsvector column */
+ if (get_attstatsslot(vardata->statsTuple,
+ TEXTOID, -1,
+ STATISTIC_KIND_MCELEM, InvalidOid,
+ &values, &nvalues,
+ &numbers, &nnumbers))
+ {
+ /*
+ * There is a most-common-elements slot for the tsvector Var, so
+ * use that.
+ */
+ selec = mcelem_tsquery_selec(query, values, nvalues,
+ numbers, nnumbers);
+ free_attstatsslot(TEXTOID, values, nvalues, numbers, nnumbers);
+ }
+ else
+ {
+ /* No most-common-elements info, so we must punt */
+ selec = (Selectivity) DEFAULT_TS_MATCH_SEL;
+ }
+ }
+ else
+ {
+ /* No stats at all, so we must punt */
+ selec = (Selectivity) DEFAULT_TS_MATCH_SEL;
+ }
+
+ return selec;
+}
+
+/*
+ * Extract data from the pg_statistic arrays into useful format.
+ */
+static Selectivity
+mcelem_tsquery_selec(TSQuery query, Datum *mcelem, int nmcelem,
+ float4 *numbers, int nnumbers)
+{
+ float4 minfreq;
+ TextFreq *lookup;
+ Selectivity selec;
+ int i;
+
+ /*
+ * There should be two more Numbers than Values, because the last two
+ * cells are taken for minimal and maximal frequency. Punt if not.
+ */
+ if (nnumbers != nmcelem + 2)
+ return DEFAULT_TS_MATCH_SEL;
+
+ /*
+ * Transpose the data into a single array so we can use bsearch().
+ */
+ lookup = (TextFreq *) palloc(sizeof(TextFreq) * nmcelem);
+ for (i = 0; i < nmcelem; i++)
+ {
+ /*
+ * The text Datums came from an array, so it cannot be compressed
+ * or stored out-of-line -- it's safe to use VARSIZE_ANY*.
+ */
+ Assert(!VARATT_IS_COMPRESSED(mcelem[i]) && !VARATT_IS_EXTERNAL(mcelem[i]));
+ lookup[i].element = (text *) DatumGetPointer(mcelem[i]);
+ lookup[i].frequency = numbers[i];
+ }
+
+ /*
+ * Grab the lowest frequency. compute_tsvector_stats() stored it for us in
+ * the one before the last cell of the Numbers array. See ts_typanalyze.c
+ */
+ minfreq = numbers[nnumbers - 2];
+
+ selec = tsquery_opr_selec(GETQUERY(query), GETOPERAND(query), lookup,
+ nmcelem, minfreq);
+
+ pfree(lookup);
+
+ return selec;
+}
+
+/*
+ * Traverse the tsquery in preorder, calculating selectivity as:
+ *
+ * selec(left_oper) * selec(right_oper) in AND nodes,
+ *
+ * selec(left_oper) + selec(right_oper) -
+ * selec(left_oper) * selec(right_oper) in OR nodes,
+ *
+ * 1 - select(oper) in NOT nodes
+ *
+ * freq[val] in VAL nodes, if the value is in MCELEM
+ * min(freq[MCELEM]) / 2 in VAL nodes, if it is not
+ *
+ *
+ * The MCELEM array is already sorted (see ts_typanalyze.c), so we can use
+ * binary search for determining freq[MCELEM].
+ */
+static Selectivity
+tsquery_opr_selec(QueryItem *item, char *operand,
+ TextFreq *lookup, int length, float4 minfreq)
+{
+ LexemeKey key;
+ TextFreq *searchres;
+ Selectivity selec, s1, s2;
+
+ /* since this function recurses, it could be driven to stack overflow */
+ check_stack_depth();
+
+ if (item->type == QI_VAL)
+ {
+ QueryOperand *oper = (QueryOperand *) item;
+
+ /*
+ * Prepare the key for bsearch().
+ */
+ key.lexeme = operand + oper->distance;
+ key.length = oper->length;
+
+ searchres = (TextFreq *) bsearch(&key, lookup, length,
+ sizeof(TextFreq),
+ compare_lexeme_textfreq);
+
+ if (searchres)
+ {
+ /*
+ * The element is in MCELEM. Return precise selectivity (or at
+ * least as precise as ANALYZE could find out).
+ */
+ return (Selectivity) searchres->frequency;
+ }
+ else
+ {
+ /*
+ * The element is not in MCELEM. Punt, but assert that the
+ * selectivity cannot be more than minfreq / 2.
+ */
+ return (Selectivity) Min(DEFAULT_TS_MATCH_SEL, minfreq / 2);
+ }
+ }
+
+ /* Current TSQuery node is an operator */
+ switch (item->operator.oper)
+ {
+ case OP_NOT:
+ selec = 1.0 - tsquery_opr_selec(item + 1, operand,
+ lookup, length, minfreq);
+ break;
+
+ case OP_AND:
+ s1 = tsquery_opr_selec(item + 1, operand,
+ lookup, length, minfreq);
+ s2 = tsquery_opr_selec(item + item->operator.left, operand,
+ lookup, length, minfreq);
+ selec = s1 * s2;
+ break;
+
+ case OP_OR:
+ s1 = tsquery_opr_selec(item + 1, operand,
+ lookup, length, minfreq);
+ s2 = tsquery_opr_selec(item + item->operator.left, operand,
+ lookup, length, minfreq);
+ selec = s1 + s2 - s1 * s2;
+ break;
+
+ default:
+ elog(ERROR, "unrecognized operator: %d", item->operator.oper);
+ selec = 0; /* keep compiler quiet */
+ break;
+ }
+
+ /* Clamp intermediate results to stay sane despite roundoff error */
+ CLAMP_PROBABILITY(selec);
+
+ return selec;
+}
+
+/*
+ * bsearch() comparator for a lexeme (non-NULL terminated string with length)
+ * and a TextFreq. Use length, then byte-for-byte comparison, because that's
+ * how ANALYZE code sorted data before storing it in a statistic tuple.
+ * See ts_typanalyze.c for details.
+ */
+static int
+compare_lexeme_textfreq(const void *e1, const void *e2)
+{
+ const LexemeKey *key = (const LexemeKey *) e1;
+ const TextFreq *t = (const TextFreq *) e2;
+ int len1,
+ len2;
+
+ len1 = key->length;
+ len2 = VARSIZE_ANY_EXHDR(t->element);
+
+ /* Compare lengths first, possibly avoiding a strncmp call */
+ if (len1 > len2)
+ return 1;
+ else if (len1 < len2)
+ return -1;
+
+ /* Fall back on byte-for-byte comparison */
+ return strncmp(key->lexeme, VARDATA_ANY(t->element), len1);
+}
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/tsearch/ts_typanalyze.c,v 1.1 2008/07/14 00:51:45 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/tsearch/ts_typanalyze.c,v 1.2 2008/09/19 19:03:40 tgl Exp $
*
*-------------------------------------------------------------------------
*/
static void prune_lexemes_hashtable(HTAB *lexemes_tab, int b_current);
static uint32 lexeme_hash(const void *key, Size keysize);
static int lexeme_match(const void *key1, const void *key2, Size keysize);
-static int trackitem_compare_desc(const void *e1, const void *e2);
+static int lexeme_compare(const void *key1, const void *key2);
+static int trackitem_compare_frequencies_desc(const void *e1, const void *e2);
+static int trackitem_compare_lexemes(const void *e1, const void *e2);
/*
int i;
TrackItem **sort_table;
int track_len;
+ int minfreq, maxfreq;
stats->stats_valid = true;
/* Do the simple null-frac and average width stats */
Assert(i == track_len);
qsort(sort_table, track_len, sizeof(TrackItem *),
- trackitem_compare_desc);
+ trackitem_compare_frequencies_desc);
/* Suppress any single-occurrence items */
while (track_len > 0)
if (num_mcelem > track_len)
num_mcelem = track_len;
+ /* Grab the minimal and maximal frequencies that will get stored */
+ minfreq = sort_table[num_mcelem - 1]->frequency;
+ maxfreq = sort_table[0]->frequency;
+
+ /*
+ * We want to store statistics sorted on the lexeme value using first
+ * length, then byte-for-byte comparison. The reason for doing length
+ * comparison first is that we don't care about the ordering so long
+ * as it's consistent, and comparing lengths first gives us a chance
+ * to avoid a strncmp() call.
+ *
+ * This is different from what we do with scalar statistics -- they get
+ * sorted on frequencies. The rationale is that we usually search
+ * through most common elements looking for a specific value, so we can
+ * grab its frequency. When values are presorted we can employ binary
+ * search for that. See ts_selfuncs.c for a real usage scenario.
+ */
+ qsort(sort_table, num_mcelem, sizeof(TrackItem *),
+ trackitem_compare_lexemes);
+
/* Generate MCELEM slot entry */
if (num_mcelem > 0)
{
/* Must copy the target values into anl_context */
old_context = MemoryContextSwitchTo(stats->anl_context);
+
+ /*
+ * We sorted statistics on the lexeme value, but we want to be
+ * able to find out the minimal and maximal frequency without
+ * going through all the values. We keep those two extra
+ * frequencies in two extra cells in mcelem_freqs.
+ */
mcelem_values = (Datum *) palloc(num_mcelem * sizeof(Datum));
- mcelem_freqs = (float4 *) palloc(num_mcelem * sizeof(float4));
+ mcelem_freqs = (float4 *) palloc((num_mcelem + 2) * sizeof(float4));
for (i = 0; i < num_mcelem; i++)
{
item->key.length));
mcelem_freqs[i] = (double) item->frequency / (double) nonnull_cnt;
}
+ mcelem_freqs[i++] = (double) minfreq / (double) nonnull_cnt;
+ mcelem_freqs[i] = (double) maxfreq / (double) nonnull_cnt;
MemoryContextSwitchTo(old_context);
stats->stakind[0] = STATISTIC_KIND_MCELEM;
stats->staop[0] = TextEqualOperator;
stats->stanumbers[0] = mcelem_freqs;
- stats->numnumbers[0] = num_mcelem;
+ /* See above comment about two extra frequency fields */
+ stats->numnumbers[0] = num_mcelem + 2;
stats->stavalues[0] = mcelem_values;
stats->numvalues[0] = num_mcelem;
/* We are storing text values */
static int
lexeme_match(const void *key1, const void *key2, Size keysize)
{
- const LexemeHashKey *d1 = (const LexemeHashKey *) key1;
- const LexemeHashKey *d2 = (const LexemeHashKey *) key2;
+ /* The keysize parameter is superfluous, the keys store their lengths */
+ return lexeme_compare(key1, key2);
+}
- /* The lexemes need to have the same length, and be memcmp-equal */
- if (d1->length == d2->length &&
- memcmp(d1->lexeme, d2->lexeme, d1->length) == 0)
- return 0;
- else
+/*
+ * Comparison function for lexemes.
+ */
+static int
+lexeme_compare(const void *key1, const void *key2)
+{
+ const LexemeHashKey *d1 = (const LexemeHashKey *) key1;
+ const LexemeHashKey *d2 = (const LexemeHashKey *) key2;
+
+ /* First, compare by length */
+ if (d1->length > d2->length)
return 1;
+ else if (d1->length < d2->length)
+ return -1;
+ /* Lengths are equal, do a byte-by-byte comparison */
+ return strncmp(d1->lexeme, d2->lexeme, d1->length);
}
/*
- * qsort() comparator for TrackItems - LC style (descending sort)
+ * qsort() comparator for sorting TrackItems on frequencies (descending sort)
*/
static int
-trackitem_compare_desc(const void *e1, const void *e2)
+trackitem_compare_frequencies_desc(const void *e1, const void *e2)
{
const TrackItem * const *t1 = (const TrackItem * const *) e1;
const TrackItem * const *t2 = (const TrackItem * const *) e2;
return (*t2)->frequency - (*t1)->frequency;
}
+
+/*
+ * qsort() comparator for sorting TrackItems on lexemes
+ */
+static int
+trackitem_compare_lexemes(const void *e1, const void *e2)
+{
+ const TrackItem * const *t1 = (const TrackItem * const *) e1;
+ const TrackItem * const *t2 = (const TrackItem * const *) e2;
+
+ return lexeme_compare(&(*t1)->key, &(*t2)->key);
+}
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.486 2008/09/15 18:43:41 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.487 2008/09/19 19:03:40 tgl Exp $
*
*-------------------------------------------------------------------------
*/
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 200809151
+#define CATALOG_VERSION_NO 200809191
#endif
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/pg_operator.h,v 1.162 2008/08/16 00:01:37 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_operator.h,v 1.163 2008/09/19 19:03:40 tgl Exp $
*
* NOTES
* the genbki.sh script reads this file and generates .bki
DATA(insert OID = 3631 ( ">=" PGNSP PGUID b f f 3614 3614 16 3628 3627 tsvector_ge scalargtsel scalargtjoinsel ));
DATA(insert OID = 3632 ( ">" PGNSP PGUID b f f 3614 3614 16 3627 3628 tsvector_gt scalargtsel scalargtjoinsel ));
DATA(insert OID = 3633 ( "||" PGNSP PGUID b f f 3614 3614 3614 0 0 tsvector_concat - - ));
-DATA(insert OID = 3636 ( "@@" PGNSP PGUID b f f 3614 3615 16 3637 0 ts_match_vq contsel contjoinsel ));
-DATA(insert OID = 3637 ( "@@" PGNSP PGUID b f f 3615 3614 16 3636 0 ts_match_qv contsel contjoinsel ));
-DATA(insert OID = 3660 ( "@@@" PGNSP PGUID b f f 3614 3615 16 3661 0 ts_match_vq contsel contjoinsel ));
-DATA(insert OID = 3661 ( "@@@" PGNSP PGUID b f f 3615 3614 16 3660 0 ts_match_qv contsel contjoinsel ));
+DATA(insert OID = 3636 ( "@@" PGNSP PGUID b f f 3614 3615 16 3637 0 ts_match_vq tsmatchsel tsmatchjoinsel ));
+DATA(insert OID = 3637 ( "@@" PGNSP PGUID b f f 3615 3614 16 3636 0 ts_match_qv tsmatchsel tsmatchjoinsel ));
+DATA(insert OID = 3660 ( "@@@" PGNSP PGUID b f f 3614 3615 16 3661 0 ts_match_vq tsmatchsel tsmatchjoinsel ));
+DATA(insert OID = 3661 ( "@@@" PGNSP PGUID b f f 3615 3614 16 3660 0 ts_match_qv tsmatchsel tsmatchjoinsel ));
DATA(insert OID = 3674 ( "<" PGNSP PGUID b f f 3615 3615 16 3679 3678 tsquery_lt scalarltsel scalarltjoinsel ));
DATA(insert OID = 3675 ( "<=" PGNSP PGUID b f f 3615 3615 16 3678 3679 tsquery_le scalarltsel scalarltjoinsel ));
DATA(insert OID = 3676 ( "=" PGNSP PGUID b t f 3615 3615 16 3676 3677 tsquery_eq eqsel eqjoinsel ));
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.514 2008/09/10 18:09:20 alvherre Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.515 2008/09/19 19:03:40 tgl Exp $
*
* NOTES
* The script catalog/genbki.sh reads this file and generates .bki
DATA(insert OID = 3701 ( gtsquery_consistent PGNSP PGUID 12 1 0 0 f f t f i 5 16 "2281 2281 23 26 2281" _null_ _null_ _null_ gtsquery_consistent _null_ _null_ _null_ ));
DESCR("GiST tsquery support");
-DATA(insert OID = 3688 ( ts_typanalyze PGNSP PGUID 12 1 0 0 f f t f s 1 16 "2281" _null_ _null_ _null_ ts_typanalyze _null_ _null_ _null_ ));
+DATA(insert OID = 3686 ( tsmatchsel PGNSP PGUID 12 1 0 0 f f t f s 4 701 "2281 26 2281 23" _null_ _null_ _null_ tsmatchsel _null_ _null_ _null_ ));
+DESCR("restriction selectivity of tsvector @@ tsquery");
+DATA(insert OID = 3687 ( tsmatchjoinsel PGNSP PGUID 12 1 0 0 f f t f s 5 701 "2281 26 2281 21 2281" _null_ _null_ _null_ tsmatchjoinsel _null_ _null_ _null_ ));
+DESCR("join selectivity of tsvector @@ tsquery");
+DATA(insert OID = 3688 ( ts_typanalyze PGNSP PGUID 12 1 0 0 f f t f s 1 16 "2281" _null_ _null_ _null_ ts_typanalyze _null_ _null_ _null_ ));
DESCR("tsvector typanalyze");
DATA(insert OID = 3689 ( ts_stat PGNSP PGUID 12 10 10000 0 f f t t v 1 2249 "25" "{25,25,23,23}" "{i,o,o,o}" "{query,word,ndoc,nentry}" ts_stat1 _null_ _null_ _null_ ));
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/pg_statistic.h,v 1.36 2008/07/14 00:51:45 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_statistic.h,v 1.37 2008/09/19 19:03:41 tgl Exp $
*
* NOTES
* the genbki.sh script reads this file and generates .bki
* values. This is useful when the column datatype is an array or some other
* type with identifiable elements (for instance, tsvector). staop contains
* the equality operator appropriate to the element type. stavalues contains
- * the most common element values, and stanumbers their frequencies, with the
- * same rules as for MCV slots.
+ * the most common element values, and stanumbers their frequencies. Unlike
+ * MCV slots, the values are sorted into order (to support binary search
+ * for a particular value). Since this puts the minimum and maximum
+ * frequencies at unpredictable spots in stanumbers, there are two extra
+ * members of stanumbers, holding copies of the minimum and maximum
+ * frequencies.
*
* Note: in current usage for tsvector columns, the stavalues elements are of
* type text, even though their representation within tsvector is not
*
* Copyright (c) 1998-2008, PostgreSQL Global Development Group
*
- * $PostgreSQL: pgsql/src/include/tsearch/ts_type.h,v 1.13 2008/07/14 00:51:45 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/tsearch/ts_type.h,v 1.14 2008/09/19 19:03:41 tgl Exp $
*
*-------------------------------------------------------------------------
*/
extern Datum ts_rankcd_ttf(PG_FUNCTION_ARGS);
extern Datum ts_rankcd_wttf(PG_FUNCTION_ARGS);
+extern Datum tsmatchsel(PG_FUNCTION_ARGS);
+extern Datum tsmatchjoinsel(PG_FUNCTION_ARGS);
+
extern Datum ts_typanalyze(PG_FUNCTION_ARGS);
projects / users / gsingh / postgres.git / commitdiff