*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.170 2005/01/28 20:34:25 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.189 2005/09/24 22:54:38 tgl Exp $
*
*-------------------------------------------------------------------------
*/
*
* The call convention for a restriction estimator (oprrest function) is
*
- * Selectivity oprrest (Query *root,
+ * Selectivity oprrest (PlannerInfo *root,
* Oid operator,
* List *args,
* int varRelid);
* except that varRelid is not needed, and instead the join type is
* supplied:
*
- * Selectivity oprjoin (Query *root,
+ * Selectivity oprjoin (PlannerInfo *root,
* Oid operator,
* List *args,
* JoinType jointype);
#include "access/heapam.h"
#include "access/nbtree.h"
#include "access/tuptoaster.h"
-#include "catalog/catname.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_operator.h"
#include "utils/datum.h"
#include "utils/int8.h"
#include "utils/lsyscache.h"
+#include "utils/nabstime.h"
#include "utils/pg_locale.h"
#include "utils/selfuncs.h"
#include "utils/syscache.h"
RelOptInfo *rel; /* Relation, or NULL if not identifiable */
HeapTuple statsTuple; /* pg_statistic tuple, or NULL if none */
/* NB: if statsTuple!=NULL, it must be freed when caller is done */
+ Oid vartype; /* exposed type of expression */
Oid atttype; /* type to pass to get_attstatsslot */
int32 atttypmod; /* typmod to pass to get_attstatsslot */
bool isunique; /* true if matched to a unique index */
Datum lobound, Datum hibound, Oid boundstypid,
double *scaledlobound, double *scaledhibound);
static double convert_numeric_to_scalar(Datum value, Oid typid);
-static void convert_string_to_scalar(unsigned char *value,
+static void convert_string_to_scalar(char *value,
double *scaledvalue,
- unsigned char *lobound,
+ char *lobound,
double *scaledlobound,
- unsigned char *hibound,
+ char *hibound,
double *scaledhibound);
static void convert_bytea_to_scalar(Datum value,
double *scaledvalue,
double *scaledlobound,
Datum hibound,
double *scaledhibound);
-static double convert_one_string_to_scalar(unsigned char *value,
+static double convert_one_string_to_scalar(char *value,
int rangelo, int rangehi);
static double convert_one_bytea_to_scalar(unsigned char *value, int valuelen,
int rangelo, int rangehi);
-static unsigned char *convert_string_datum(Datum value, Oid typid);
+static char *convert_string_datum(Datum value, Oid typid);
static double convert_timevalue_to_scalar(Datum value, Oid typid);
-static bool get_restriction_variable(Query *root, List *args, int varRelid,
+static bool get_restriction_variable(PlannerInfo *root, List *args, int varRelid,
VariableStatData *vardata, Node **other,
bool *varonleft);
-static void get_join_variables(Query *root, List *args,
+static void get_join_variables(PlannerInfo *root, List *args,
VariableStatData *vardata1,
VariableStatData *vardata2);
-static void examine_variable(Query *root, Node *node, int varRelid,
+static void examine_variable(PlannerInfo *root, Node *node, int varRelid,
VariableStatData *vardata);
static double get_variable_numdistinct(VariableStatData *vardata);
-static bool get_variable_maximum(Query *root, VariableStatData *vardata,
+static bool get_variable_maximum(PlannerInfo *root, VariableStatData *vardata,
Oid sortop, Datum *max);
-static Selectivity prefix_selectivity(Query *root, VariableStatData *vardata,
+static Selectivity prefix_selectivity(PlannerInfo *root, Node *variable,
Oid opclass, Const *prefix);
static Selectivity pattern_selectivity(Const *patt, Pattern_Type ptype);
static Datum string_to_datum(const char *str, Oid datatype);
Datum
eqsel(PG_FUNCTION_ARGS)
{
- Query *root = (Query *) PG_GETARG_POINTER(0);
+ PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
Datum
neqsel(PG_FUNCTION_ARGS)
{
- Query *root = (Query *) PG_GETARG_POINTER(0);
+ PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
* it will return a default estimate.
*/
static double
-scalarineqsel(Query *root, Oid operator, bool isgt,
+scalarineqsel(PlannerInfo *root, Oid operator, bool isgt,
VariableStatData *vardata, Datum constval, Oid consttype)
{
Form_pg_statistic stats;
*/
if (convert_to_scalar(constval, consttype, &val,
values[i - 1], values[i],
- vardata->atttype,
+ vardata->vartype,
&low, &high))
{
if (high <= low)
Datum
scalarltsel(PG_FUNCTION_ARGS)
{
- Query *root = (Query *) PG_GETARG_POINTER(0);
+ PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
Datum
scalargtsel(PG_FUNCTION_ARGS)
{
- Query *root = (Query *) PG_GETARG_POINTER(0);
+ PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
static double
patternsel(PG_FUNCTION_ARGS, Pattern_Type ptype)
{
- Query *root = (Query *) PG_GETARG_POINTER(0);
+ PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
#ifdef NOT_USED
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
VariableStatData vardata;
+ Node *variable;
Node *other;
bool varonleft;
Datum constval;
ReleaseVariableStats(vardata);
return DEFAULT_MATCH_SEL;
}
+ variable = (Node *) linitial(args);
/*
* If the constant is NULL, assume operator is strict and return zero,
}
/*
- * The var, on the other hand, might be a binary-compatible type;
- * particularly a domain. Try to fold it if it's not recognized
- * immediately.
- */
- vartype = vardata.atttype;
- if (vartype != consttype)
- vartype = getBaseType(vartype);
-
- /*
- * We should now be able to recognize the var's datatype. Choose the
- * index opclass from which we must draw the comparison operators.
+ * Similarly, the exposed type of the left-hand side should be one
+ * of those we know. (Do not look at vardata.atttype, which might be
+ * something binary-compatible but different.) We can use it to choose
+ * the index opclass from which we must draw the comparison operators.
*
* NOTE: It would be more correct to use the PATTERN opclasses than the
* simple ones, but at the moment ANALYZE will not generate statistics
* for the PATTERN operators. But our results are so approximate
* anyway that it probably hardly matters.
*/
+ vartype = vardata.vartype;
+
switch (vartype)
{
case TEXTOID:
if (eqopr == InvalidOid)
elog(ERROR, "no = operator for opclass %u", opclass);
- eqargs = list_make2(vardata.var, prefix);
+ eqargs = list_make2(variable, prefix);
result = DatumGetFloat8(DirectFunctionCall4(eqsel,
PointerGetDatum(root),
ObjectIdGetDatum(eqopr),
Selectivity selec;
if (pstatus == Pattern_Prefix_Partial)
- prefixsel = prefix_selectivity(root, &vardata, opclass, prefix);
+ prefixsel = prefix_selectivity(root, variable, opclass, prefix);
else
prefixsel = 1.0;
restsel = pattern_selectivity(rest, ptype);
* booltestsel - Selectivity of BooleanTest Node.
*/
Selectivity
-booltestsel(Query *root, BoolTestType booltesttype, Node *arg,
+booltestsel(PlannerInfo *root, BoolTestType booltesttype, Node *arg,
int varRelid, JoinType jointype)
{
VariableStatData vardata;
* nulltestsel - Selectivity of NullTest Node.
*/
Selectivity
-nulltestsel(Query *root, NullTestType nulltesttype, Node *arg, int varRelid)
+nulltestsel(PlannerInfo *root, NullTestType nulltesttype,
+ Node *arg, int varRelid)
{
VariableStatData vardata;
double selec;
Datum
eqjoinsel(PG_FUNCTION_ARGS)
{
- Query *root = (Query *) PG_GETARG_POINTER(0);
+ PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
JoinType jointype = (JoinType) PG_GETARG_INT16(3);
Datum
neqjoinsel(PG_FUNCTION_ARGS)
{
- Query *root = (Query *) PG_GETARG_POINTER(0);
+ PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
JoinType jointype = (JoinType) PG_GETARG_INT16(3);
* variable.
*/
void
-mergejoinscansel(Query *root, Node *clause,
+mergejoinscansel(PlannerInfo *root, Node *clause,
Selectivity *leftscan,
Selectivity *rightscan)
{
} GroupVarInfo;
static List *
-add_unique_group_var(Query *root, List *varinfos,
+add_unique_group_var(PlannerInfo *root, List *varinfos,
Node *var, VariableStatData *vardata)
{
GroupVarInfo *varinfo;
* do better).
*/
double
-estimate_num_groups(Query *root, List *groupExprs, double input_rows)
+estimate_num_groups(PlannerInfo *root, List *groupExprs, double input_rows)
{
List *varinfos = NIL;
double numdistinct;
GroupVarInfo *varinfo1 = (GroupVarInfo *) linitial(varinfos);
RelOptInfo *rel = varinfo1->rel;
double reldistinct = varinfo1->ndistinct;
+ double relmaxndistinct = reldistinct;
int relvarcount = 1;
List *newvarinfos = NIL;
if (varinfo2->rel == varinfo1->rel)
{
reldistinct *= varinfo2->ndistinct;
+ if (relmaxndistinct < varinfo2->ndistinct)
+ relmaxndistinct = varinfo2->ndistinct;
relvarcount++;
}
else
/*
* Clamp to size of rel, or size of rel / 10 if multiple Vars.
* The fudge factor is because the Vars are probably correlated
- * but we don't know by how much.
+ * but we don't know by how much. We should never clamp to less
+ * than the largest ndistinct value for any of the Vars, though,
+ * since there will surely be at least that many groups.
*/
double clamp = rel->tuples;
if (relvarcount > 1)
+ {
clamp *= 0.1;
+ if (clamp < relmaxndistinct)
+ {
+ clamp = relmaxndistinct;
+ /* for sanity in case some ndistinct is too large: */
+ if (clamp > rel->tuples)
+ clamp = rel->tuples;
+ }
+ }
if (reldistinct > clamp)
reldistinct = clamp;
* inner rel is well-dispersed (or the alternatives seem much worse).
*/
Selectivity
-estimate_hash_bucketsize(Query *root, Node *hashkey, int nbuckets)
+estimate_hash_bucketsize(PlannerInfo *root, Node *hashkey, double nbuckets)
{
VariableStatData vardata;
double estfract,
* the number of buckets is less than the expected number of distinct
* values; otherwise it is 1/ndistinct.
*/
- if (ndistinct > (double) nbuckets)
- estfract = 1.0 / (double) nbuckets;
+ if (ndistinct > nbuckets)
+ estfract = 1.0 / nbuckets;
else
estfract = 1.0 / ndistinct;
double *scaledlobound, double *scaledhibound)
{
/*
- * In present usage, we can assume that the valuetypid exactly matches
- * the declared input type of the operator we are invoked for (because
- * constant-folding will ensure that any Const passed to the operator
- * has been reduced to the correct type). However, the boundstypid is
- * the type of some variable that might be only binary-compatible with
- * the declared type; in particular it might be a domain type. Must
- * fold the variable type down to base type so we can recognize it.
- * (But we can skip that lookup if the variable type matches the
- * const.)
+ * Both the valuetypid and the boundstypid should exactly match
+ * the declared input type(s) of the operator we are invoked for,
+ * so we just error out if either is not recognized.
+ *
+ * XXX The histogram we are interpolating between points of could belong
+ * to a column that's only binary-compatible with the declared type.
+ * In essence we are assuming that the semantics of binary-compatible
+ * types are enough alike that we can use a histogram generated with one
+ * type's operators to estimate selectivity for the other's. This is
+ * outright wrong in some cases --- in particular signed versus unsigned
+ * interpretation could trip us up. But it's useful enough in the
+ * majority of cases that we do it anyway. Should think about more
+ * rigorous ways to do it.
*/
- if (boundstypid != valuetypid)
- boundstypid = getBaseType(boundstypid);
-
switch (valuetypid)
{
/*
case TEXTOID:
case NAMEOID:
{
- unsigned char *valstr = convert_string_datum(value, valuetypid);
- unsigned char *lostr = convert_string_datum(lobound, boundstypid);
- unsigned char *histr = convert_string_datum(hibound, boundstypid);
+ char *valstr = convert_string_datum(value, valuetypid);
+ char *lostr = convert_string_datum(lobound, boundstypid);
+ char *histr = convert_string_datum(hibound, boundstypid);
convert_string_to_scalar(valstr, scaledvalue,
lostr, scaledlobound,
return true;
}
/* Don't know how to convert */
+ *scaledvalue = *scaledlobound = *scaledhibound = 0;
return false;
}
* so this is more likely to happen than you might think.)
*/
static void
-convert_string_to_scalar(unsigned char *value,
+convert_string_to_scalar(char *value,
double *scaledvalue,
- unsigned char *lobound,
+ char *lobound,
double *scaledlobound,
- unsigned char *hibound,
+ char *hibound,
double *scaledhibound)
{
int rangelo,
rangehi;
- unsigned char *sptr;
+ char *sptr;
- rangelo = rangehi = hibound[0];
+ rangelo = rangehi = (unsigned char) hibound[0];
for (sptr = lobound; *sptr; sptr++)
{
- if (rangelo > *sptr)
- rangelo = *sptr;
- if (rangehi < *sptr)
- rangehi = *sptr;
+ if (rangelo > (unsigned char) *sptr)
+ rangelo = (unsigned char) *sptr;
+ if (rangehi < (unsigned char) *sptr)
+ rangehi = (unsigned char) *sptr;
}
for (sptr = hibound; *sptr; sptr++)
{
- if (rangelo > *sptr)
- rangelo = *sptr;
- if (rangehi < *sptr)
- rangehi = *sptr;
+ if (rangelo > (unsigned char) *sptr)
+ rangelo = (unsigned char) *sptr;
+ if (rangehi < (unsigned char) *sptr)
+ rangehi = (unsigned char) *sptr;
}
/* If range includes any upper-case ASCII chars, make it include all */
if (rangelo <= 'Z' && rangehi >= 'A')
}
static double
-convert_one_string_to_scalar(unsigned char *value, int rangelo, int rangehi)
+convert_one_string_to_scalar(char *value, int rangelo, int rangehi)
{
- int slen = strlen((char *) value);
+ int slen = strlen(value);
double num,
denom,
base;
denom = base;
while (slen-- > 0)
{
- int ch = *value++;
+ int ch = (unsigned char) *value++;
if (ch < rangelo)
ch = rangelo - 1;
* When using a non-C locale, we must pass the string through strxfrm()
* before continuing, so as to generate correct locale-specific results.
*/
-static unsigned char *
+static char *
convert_string_datum(Datum value, Oid typid)
{
char *val;
val = xfrmstr;
}
- return (unsigned char *) val;
+ return val;
}
/*
* too accurate, but plenty good enough for our purposes.
*/
#ifdef HAVE_INT64_TIMESTAMP
- return (interval->time + (interval->month * ((365.25 / 12.0) * 86400000000.0)));
+ return interval->time + interval->day * (double)USECS_PER_DAY +
+ interval->month * ((DAYS_PER_YEAR / (double)MONTHS_PER_YEAR) * USECS_PER_DAY);
#else
- return interval->time +
- interval ->month * (365.25 / 12.0 * 24.0 * 60.0 * 60.0);
+ return interval->time + interval->day * SECS_PER_DAY +
+ interval->month * ((DAYS_PER_YEAR / (double)MONTHS_PER_YEAR) * (double)SECS_PER_DAY);
#endif
}
case RELTIMEOID:
#endif
case TINTERVALOID:
{
- TimeInterval interval = DatumGetTimeInterval(value);
+ TimeInterval tinterval = DatumGetTimeInterval(value);
#ifdef HAVE_INT64_TIMESTAMP
- if (interval->status != 0)
- return ((interval->data[1] - interval->data[0]) *1000000.0);
+ if (tinterval->status != 0)
+ return ((tinterval->data[1] - tinterval->data[0]) * 1000000.0);
#else
- if (interval->status != 0)
- return interval->data[1] - interval->data[0];
+ if (tinterval->status != 0)
+ return tinterval->data[1] - tinterval->data[0];
#endif
return 0; /* for lack of a better idea */
}
* and also indicate which side it was on and the other argument.
*
* Inputs:
- * root: the Query
+ * root: the planner info
* args: clause argument list
* varRelid: see specs for restriction selectivity functions
*
* Outputs: (these are valid only if TRUE is returned)
* *vardata: gets information about variable (see examine_variable)
- * *other: gets other clause argument, stripped of binary relabeling,
- * and aggressively reduced to a constant
+ * *other: gets other clause argument, aggressively reduced to a constant
* *varonleft: set TRUE if variable is on the left, FALSE if on the right
*
* Returns TRUE if a variable is identified, otherwise FALSE.
* callers are expecting that the other side will act like a pseudoconstant.
*/
static bool
-get_restriction_variable(Query *root, List *args, int varRelid,
+get_restriction_variable(PlannerInfo *root, List *args, int varRelid,
VariableStatData *vardata, Node **other,
bool *varonleft)
{
* Apply examine_variable() to each side of a join clause.
*/
static void
-get_join_variables(Query *root, List *args,
+get_join_variables(PlannerInfo *root, List *args,
VariableStatData *vardata1, VariableStatData *vardata2)
{
Node *left,
* Fill in a VariableStatData struct to describe the expression.
*
* Inputs:
- * root: the Query
+ * root: the planner info
* node: the expression tree to examine
* varRelid: see specs for restriction selectivity functions
*
* Outputs: *vardata is filled as follows:
- * var: the input expression (with any binary relabeling stripped)
+ * var: the input expression (with any binary relabeling stripped, if
+ * it is or contains a variable; but otherwise the type is preserved)
* rel: RelOptInfo for relation containing variable; NULL if expression
* contains no Vars (NOTE this could point to a RelOptInfo of a
* subquery, not one in the current query).
* statsTuple: the pg_statistic entry for the variable, if one exists;
* otherwise NULL.
+ * vartype: exposed type of the expression; this should always match
+ * the declared input type of the operator we are estimating for.
* atttype, atttypmod: type data to pass to get_attstatsslot(). This is
* commonly the same as the exposed type of the variable argument,
* but can be different in binary-compatible-type cases.
* Caller is responsible for doing ReleaseVariableStats() before exiting.
*/
static void
-examine_variable(Query *root, Node *node, int varRelid,
+examine_variable(PlannerInfo *root, Node *node, int varRelid,
VariableStatData *vardata)
{
+ Node *basenode;
Relids varnos;
RelOptInfo *onerel;
/* Make sure we don't return dangling pointers in vardata */
MemSet(vardata, 0, sizeof(VariableStatData));
- /* Ignore any binary-compatible relabeling */
+ /* Save the exposed type of the expression */
+ vardata->vartype = exprType(node);
- if (IsA(node, RelabelType))
- node = (Node *) ((RelabelType *) node)->arg;
+ /* Look inside any binary-compatible relabeling */
- vardata->var = node;
+ if (IsA(node, RelabelType))
+ basenode = (Node *) ((RelabelType *) node)->arg;
+ else
+ basenode = node;
/* Fast path for a simple Var */
- if (IsA(node, Var) &&
- (varRelid == 0 || varRelid == ((Var *) node)->varno))
+ if (IsA(basenode, Var) &&
+ (varRelid == 0 || varRelid == ((Var *) basenode)->varno))
{
- Var *var = (Var *) node;
+ Var *var = (Var *) basenode;
Oid relid;
+ vardata->var = basenode; /* return Var without relabeling */
vardata->rel = find_base_rel(root, var->varno);
vardata->atttype = var->vartype;
vardata->atttypmod = var->vartypmod;
- relid = getrelid(var->varno, root->rtable);
+ relid = getrelid(var->varno, root->parse->rtable);
if (OidIsValid(relid))
{
* membership. Note that when varRelid isn't zero, only vars of that
* relation are considered "real" vars.
*/
- varnos = pull_varnos(node);
+ varnos = pull_varnos(basenode);
onerel = NULL;
onerel = find_base_rel(root,
(varRelid ? varRelid : bms_singleton_member(varnos)));
vardata->rel = onerel;
+ node = basenode; /* strip any relabeling */
}
/* else treat it as a constant */
break;
{
/* treat it as a variable of a join relation */
vardata->rel = find_join_rel(root, varnos);
+ node = basenode; /* strip any relabeling */
}
else if (bms_is_member(varRelid, varnos))
{
/* ignore the vars belonging to other relations */
vardata->rel = find_base_rel(root, varRelid);
+ node = basenode; /* strip any relabeling */
/* note: no point in expressional-index search here */
}
/* else treat it as a constant */
bms_free(varnos);
+ vardata->var = node;
vardata->atttype = exprType(node);
vardata->atttypmod = exprTypmod(node);
stats = (Form_pg_statistic) GETSTRUCT(vardata->statsTuple);
stadistinct = stats->stadistinct;
}
- else if (vardata->atttype == BOOLOID)
+ else if (vardata->vartype == BOOLOID)
{
/*
* Special-case boolean columns: presumably, two distinct values.
* minimum instead of the maximum, just pass the ">" operator instead.)
*/
static bool
-get_variable_maximum(Query *root, VariableStatData *vardata,
+get_variable_maximum(PlannerInfo *root, VariableStatData *vardata,
Oid sortop, Datum *max)
{
Datum tmax = 0;
* Estimate the selectivity of a fixed prefix for a pattern match.
*
* A fixed prefix "foo" is estimated as the selectivity of the expression
- * "variable >= 'foo' AND variable < 'fop'" (see also indxqual.c).
+ * "variable >= 'foo' AND variable < 'fop'" (see also indxpath.c).
*
* We use the >= and < operators from the specified btree opclass to do the
* estimation. The given variable and Const must be of the associated
* more useful to use the upper-bound code than not.
*/
static Selectivity
-prefix_selectivity(Query *root, VariableStatData *vardata,
+prefix_selectivity(PlannerInfo *root, Node *variable,
Oid opclass, Const *prefixcon)
{
Selectivity prefixsel;
BTGreaterEqualStrategyNumber);
if (cmpopr == InvalidOid)
elog(ERROR, "no >= operator for opclass %u", opclass);
- cmpargs = list_make2(vardata->var, prefixcon);
+ cmpargs = list_make2(variable, prefixcon);
/* Assume scalargtsel is appropriate for all supported types */
prefixsel = DatumGetFloat8(DirectFunctionCall4(scalargtsel,
PointerGetDatum(root),
BTLessStrategyNumber);
if (cmpopr == InvalidOid)
elog(ERROR, "no < operator for opclass %u", opclass);
- cmpargs = list_make2(vardata->var, greaterstrcon);
+ cmpargs = list_make2(variable, greaterstrcon);
/* Assume scalarltsel is appropriate for all supported types */
topsel = DatumGetFloat8(DirectFunctionCall4(scalarltsel,
PointerGetDatum(root),
prefixsel = topsel + prefixsel - 1.0;
/* Adjust for double-exclusion of NULLs */
- prefixsel += nulltestsel(root, IS_NULL, vardata->var, 0);
+ prefixsel += nulltestsel(root, IS_NULL, variable, 0);
/*
* A zero or slightly negative prefixsel should be converted into
*
* NOTE: at present this assumes we are in the C locale, so that simple
* bytewise comparison applies. However, we might be in a multibyte
- * encoding such as UTF-8, so we do have to watch out for generating
+ * encoding such as UTF8, so we do have to watch out for generating
* invalid encoding sequences.
*/
Const *
if (datatype != BYTEAOID)
{
/* do not generate invalid encoding sequences */
- if (!pg_verifymbstr((const unsigned char *) workstr,
- len, true))
+ if (!pg_verifymbstr(workstr, len, true))
continue;
workstr_const = string_to_const(workstr, datatype);
}
* byte, depending on the character encoding.
*/
if (datatype != BYTEAOID && pg_database_encoding_max_length() > 1)
- len = pg_mbcliplen((const unsigned char *) workstr, len, len - 1);
+ len = pg_mbcliplen(workstr, len, len - 1);
else
len -= 1;
* don't have any better idea about how to estimate. Index-type-specific
* knowledge can be incorporated in the type-specific routines.
*
+ * One bit of index-type-specific knowledge we can relatively easily use
+ * in genericcostestimate is the estimate of the number of index tuples
+ * visited. If numIndexTuples is not 0 then it is used as the estimate,
+ * otherwise we compute a generic estimate.
+ *
*-------------------------------------------------------------------------
*/
static void
-genericcostestimate(Query *root, RelOptInfo *rel,
+genericcostestimate(PlannerInfo *root,
IndexOptInfo *index, List *indexQuals,
+ double numIndexTuples,
Cost *indexStartupCost,
Cost *indexTotalCost,
Selectivity *indexSelectivity,
double *indexCorrelation)
{
- double numIndexTuples;
double numIndexPages;
QualCost index_qual_cost;
double qual_op_cost;
* of partial redundancy (such as "x < 4" from the qual and "x < 5"
* from the predicate) will be recognized and handled correctly by
* clauselist_selectivity(). This assumption is somewhat fragile,
- * since it depends on pred_test() and clauselist_selectivity() having
- * similar capabilities, and there are certainly many cases where we
- * will end up with a too-low selectivity estimate. This will bias
- * the system in favor of using partial indexes where possible, which
- * is not necessarily a bad thing. But it'd be nice to do better
- * someday.
+ * since it depends on predicate_implied_by() and clauselist_selectivity()
+ * having similar capabilities, and there are certainly many cases where
+ * we will end up with a too-low selectivity estimate. This will bias the
+ * system in favor of using partial indexes where possible, which is not
+ * necessarily a bad thing. But it'd be nice to do better someday.
*
* Note that index->indpred and indexQuals are both in implicit-AND form,
* so ANDing them together just takes merging the lists. However,
/* Estimate the fraction of main-table tuples that will be visited */
*indexSelectivity = clauselist_selectivity(root, selectivityQuals,
- rel->relid,
+ index->rel->relid,
JOIN_INNER);
/*
- * Estimate the number of tuples that will be visited. We do it in
- * this rather peculiar-looking way in order to get the right answer
- * for partial indexes. We can bound the number of tuples by the
- * index size, in any case.
+ * If caller didn't give us an estimate, estimate the number of index
+ * tuples that will be visited. We do it in this rather peculiar-looking
+ * way in order to get the right answer for partial indexes.
*/
- numIndexTuples = *indexSelectivity * rel->tuples;
-
- if (numIndexTuples > index->tuples)
- numIndexTuples = index->tuples;
+ if (numIndexTuples <= 0.0)
+ numIndexTuples = *indexSelectivity * index->rel->tuples;
/*
- * Always estimate at least one tuple is touched, even when
+ * We can bound the number of tuples by the index size in any case.
+ * Also, always estimate at least one tuple is touched, even when
* indexSelectivity estimate is tiny.
*/
+ if (numIndexTuples > index->tuples)
+ numIndexTuples = index->tuples;
if (numIndexTuples < 1.0)
numIndexTuples = 1.0;
Datum
btcostestimate(PG_FUNCTION_ARGS)
{
- Query *root = (Query *) PG_GETARG_POINTER(0);
- RelOptInfo *rel = (RelOptInfo *) PG_GETARG_POINTER(1);
- IndexOptInfo *index = (IndexOptInfo *) PG_GETARG_POINTER(2);
- List *indexQuals = (List *) PG_GETARG_POINTER(3);
- Cost *indexStartupCost = (Cost *) PG_GETARG_POINTER(4);
- Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(5);
- Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(6);
- double *indexCorrelation = (double *) PG_GETARG_POINTER(7);
+ PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
+ IndexOptInfo *index = (IndexOptInfo *) PG_GETARG_POINTER(1);
+ List *indexQuals = (List *) PG_GETARG_POINTER(2);
+ Cost *indexStartupCost = (Cost *) PG_GETARG_POINTER(3);
+ Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(4);
+ Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(5);
+ double *indexCorrelation = (double *) PG_GETARG_POINTER(6);
Oid relid;
AttrNumber colnum;
HeapTuple tuple;
+ double numIndexTuples;
+ List *indexBoundQuals;
+ int indexcol;
+ bool eqQualHere;
+ ListCell *l;
+
+ /*
+ * For a btree scan, only leading '=' quals plus inequality quals
+ * for the immediately next attribute contribute to index selectivity
+ * (these are the "boundary quals" that determine the starting and
+ * stopping points of the index scan). Additional quals can suppress
+ * visits to the heap, so it's OK to count them in indexSelectivity,
+ * but they should not count for estimating numIndexTuples. So we must
+ * examine the given indexQuals to find out which ones count as boundary
+ * quals. We rely on the knowledge that they are given in index column
+ * order.
+ */
+ indexBoundQuals = NIL;
+ indexcol = 0;
+ eqQualHere = false;
+ foreach(l, indexQuals)
+ {
+ RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
+ Expr *clause;
+ Oid clause_op;
+ int op_strategy;
+
+ Assert(IsA(rinfo, RestrictInfo));
+ clause = rinfo->clause;
+ Assert(IsA(clause, OpExpr));
+ clause_op = ((OpExpr *) clause)->opno;
+ if (match_index_to_operand(get_leftop(clause), indexcol, index))
+ {
+ /* clause_op is correct */
+ }
+ else if (match_index_to_operand(get_rightop(clause), indexcol, index))
+ {
+ /* Must flip operator to get the opclass member */
+ clause_op = get_commutator(clause_op);
+ }
+ else
+ {
+ /* Must be past the end of quals for indexcol, try next */
+ if (!eqQualHere)
+ break; /* done if no '=' qual for indexcol */
+ indexcol++;
+ eqQualHere = false;
+ if (match_index_to_operand(get_leftop(clause), indexcol, index))
+ {
+ /* clause_op is correct */
+ }
+ else if (match_index_to_operand(get_rightop(clause),
+ indexcol, index))
+ {
+ /* Must flip operator to get the opclass member */
+ clause_op = get_commutator(clause_op);
+ }
+ else
+ {
+ /* No quals for new indexcol, so we are done */
+ break;
+ }
+ }
+ op_strategy = get_op_opclass_strategy(clause_op,
+ index->classlist[indexcol]);
+ Assert(op_strategy != 0); /* not a member of opclass?? */
+ if (op_strategy == BTEqualStrategyNumber)
+ eqQualHere = true;
+ indexBoundQuals = lappend(indexBoundQuals, rinfo);
+ }
+
+ /*
+ * If index is unique and we found an '=' clause for each column,
+ * we can just assume numIndexTuples = 1 and skip the expensive
+ * clauselist_selectivity calculations.
+ */
+ if (index->unique && indexcol == index->ncolumns - 1 && eqQualHere)
+ numIndexTuples = 1.0;
+ else
+ {
+ Selectivity btreeSelectivity;
+
+ btreeSelectivity = clauselist_selectivity(root, indexBoundQuals,
+ index->rel->relid,
+ JOIN_INNER);
+ numIndexTuples = btreeSelectivity * index->rel->tuples;
+ }
- genericcostestimate(root, rel, index, indexQuals,
+ genericcostestimate(root, index, indexQuals, numIndexTuples,
indexStartupCost, indexTotalCost,
indexSelectivity, indexCorrelation);
/*
* If we can get an estimate of the first column's ordering
* correlation C from pg_statistic, estimate the index correlation as
- * C for a single- column index, or C * 0.75 for multiple columns.
+ * C for a single-column index, or C * 0.75 for multiple columns.
* (The idea here is that multiple columns dilute the importance of
* the first column's ordering, but don't negate it entirely. Before
* 8.0 we divided the correlation by the number of columns, but that
if (index->indexkeys[0] != 0)
{
/* Simple variable --- look to stats for the underlying table */
- relid = getrelid(rel->relid, root->rtable);
+ relid = getrelid(index->rel->relid, root->parse->rtable);
Assert(relid != InvalidOid);
colnum = index->indexkeys[0];
}
Datum
rtcostestimate(PG_FUNCTION_ARGS)
{
- Query *root = (Query *) PG_GETARG_POINTER(0);
- RelOptInfo *rel = (RelOptInfo *) PG_GETARG_POINTER(1);
- IndexOptInfo *index = (IndexOptInfo *) PG_GETARG_POINTER(2);
- List *indexQuals = (List *) PG_GETARG_POINTER(3);
- Cost *indexStartupCost = (Cost *) PG_GETARG_POINTER(4);
- Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(5);
- Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(6);
- double *indexCorrelation = (double *) PG_GETARG_POINTER(7);
-
- genericcostestimate(root, rel, index, indexQuals,
+ PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
+ IndexOptInfo *index = (IndexOptInfo *) PG_GETARG_POINTER(1);
+ List *indexQuals = (List *) PG_GETARG_POINTER(2);
+ Cost *indexStartupCost = (Cost *) PG_GETARG_POINTER(3);
+ Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(4);
+ Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(5);
+ double *indexCorrelation = (double *) PG_GETARG_POINTER(6);
+
+ genericcostestimate(root, index, indexQuals, 0.0,
indexStartupCost, indexTotalCost,
indexSelectivity, indexCorrelation);
Datum
hashcostestimate(PG_FUNCTION_ARGS)
{
- Query *root = (Query *) PG_GETARG_POINTER(0);
- RelOptInfo *rel = (RelOptInfo *) PG_GETARG_POINTER(1);
- IndexOptInfo *index = (IndexOptInfo *) PG_GETARG_POINTER(2);
- List *indexQuals = (List *) PG_GETARG_POINTER(3);
- Cost *indexStartupCost = (Cost *) PG_GETARG_POINTER(4);
- Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(5);
- Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(6);
- double *indexCorrelation = (double *) PG_GETARG_POINTER(7);
-
- genericcostestimate(root, rel, index, indexQuals,
+ PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
+ IndexOptInfo *index = (IndexOptInfo *) PG_GETARG_POINTER(1);
+ List *indexQuals = (List *) PG_GETARG_POINTER(2);
+ Cost *indexStartupCost = (Cost *) PG_GETARG_POINTER(3);
+ Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(4);
+ Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(5);
+ double *indexCorrelation = (double *) PG_GETARG_POINTER(6);
+
+ genericcostestimate(root, index, indexQuals, 0.0,
indexStartupCost, indexTotalCost,
indexSelectivity, indexCorrelation);
Datum
gistcostestimate(PG_FUNCTION_ARGS)
{
- Query *root = (Query *) PG_GETARG_POINTER(0);
- RelOptInfo *rel = (RelOptInfo *) PG_GETARG_POINTER(1);
- IndexOptInfo *index = (IndexOptInfo *) PG_GETARG_POINTER(2);
- List *indexQuals = (List *) PG_GETARG_POINTER(3);
- Cost *indexStartupCost = (Cost *) PG_GETARG_POINTER(4);
- Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(5);
- Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(6);
- double *indexCorrelation = (double *) PG_GETARG_POINTER(7);
-
- genericcostestimate(root, rel, index, indexQuals,
+ PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
+ IndexOptInfo *index = (IndexOptInfo *) PG_GETARG_POINTER(1);
+ List *indexQuals = (List *) PG_GETARG_POINTER(2);
+ Cost *indexStartupCost = (Cost *) PG_GETARG_POINTER(3);
+ Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(4);
+ Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(5);
+ double *indexCorrelation = (double *) PG_GETARG_POINTER(6);
+
+ genericcostestimate(root, index, indexQuals, 0.0,
indexStartupCost, indexTotalCost,
indexSelectivity, indexCorrelation);
projects / postgresql / blobdiff