diff --git a/contrib/file_fdw/file_fdw.c b/contrib/file_fdw/file_fdw.c
index 30ed9fbad1..2d36a72e9f 100644
--- a/contrib/file_fdw/file_fdw.c
+++ b/contrib/file_fdw/file_fdw.c
@@ -125,7 +125,9 @@ static void fileBeginForeignScan(ForeignScanState *node, int eflags);
static TupleTableSlot *fileIterateForeignScan(ForeignScanState *node);
static void fileReScanForeignScan(ForeignScanState *node);
static void fileEndForeignScan(ForeignScanState *node);
-static AcquireSampleRowsFunc fileAnalyzeForeignTable(Relation relation);
+static bool fileAnalyzeForeignTable(Relation relation,
+ AcquireSampleRowsFunc *func,
+ BlockNumber *totalpages);
/*
* Helper functions
@@ -141,8 +143,7 @@ static void estimate_costs(PlannerInfo *root, RelOptInfo *baserel,
Cost *startup_cost, Cost *total_cost);
static int file_acquire_sample_rows(Relation onerel, int elevel,
HeapTuple *rows, int targrows,
- double *totalrows, double *totaldeadrows,
- BlockNumber *totalpages);
+ double *totalrows, double *totaldeadrows);
/*
@@ -656,10 +657,39 @@ fileEndForeignScan(ForeignScanState *node)
* fileAnalyzeForeignTable
* Test whether analyzing this foreign table is supported
*/
-static AcquireSampleRowsFunc
-fileAnalyzeForeignTable(Relation relation)
+static bool
+fileAnalyzeForeignTable(Relation relation,
+ AcquireSampleRowsFunc *func,
+ BlockNumber *totalpages)
{
- return file_acquire_sample_rows;
+ char *filename;
+ List *options;
+ struct stat stat_buf;
+
+ /* Fetch options of foreign table */
+ fileGetOptions(RelationGetRelid(relation), &filename, &options);
+
+ /*
+ * Get size of the file. (XXX if we fail here, would it be better to
+ * just return false to skip analyzing the table?)
+ */
+ if (stat(filename, &stat_buf) < 0)
+ ereport(ERROR,
+ (errcode_for_file_access(),
+ errmsg("could not stat file \"%s\": %m",
+ filename)));
+
+ /*
+ * Convert size to pages. Must return at least 1 so that we can tell
+ * later on that pg_class.relpages is not default.
+ */
+ *totalpages = (stat_buf.st_size + (BLCKSZ - 1)) / BLCKSZ;
+ if (*totalpages < 1)
+ *totalpages = 1;
+
+ *func = file_acquire_sample_rows;
+
+ return true;
}
/*
@@ -780,8 +810,7 @@ estimate_costs(PlannerInfo *root, RelOptInfo *baserel,
* which must have at least targrows entries.
* The actual number of rows selected is returned as the function result.
* We also count the total number of rows in the file and return it into
- * *totalrows, and return the file's physical size in *totalpages.
- * Note that *totaldeadrows is always set to 0.
+ * *totalrows. Note that *totaldeadrows is always set to 0.
*
* Note that the returned list of rows is not always in order by physical
* position in the file. Therefore, correlation estimates derived later
@@ -791,8 +820,7 @@ estimate_costs(PlannerInfo *root, RelOptInfo *baserel,
static int
file_acquire_sample_rows(Relation onerel, int elevel,
HeapTuple *rows, int targrows,
- double *totalrows, double *totaldeadrows,
- BlockNumber *totalpages)
+ double *totalrows, double *totaldeadrows)
{
int numrows = 0;
double rowstoskip = -1; /* -1 means not set yet */
@@ -802,7 +830,6 @@ file_acquire_sample_rows(Relation onerel, int elevel,
bool *nulls;
bool found;
char *filename;
- struct stat stat_buf;
List *options;
CopyState cstate;
ErrorContextCallback errcontext;
@@ -819,22 +846,6 @@ file_acquire_sample_rows(Relation onerel, int elevel,
/* Fetch options of foreign table */
fileGetOptions(RelationGetRelid(onerel), &filename, &options);
- /*
- * Get size of the file.
- */
- if (stat(filename, &stat_buf) < 0)
- ereport(ERROR,
- (errcode_for_file_access(),
- errmsg("could not stat file \"%s\": %m",
- filename)));
-
- /*
- * Convert size to pages for use in I/O cost estimate.
- */
- *totalpages = (stat_buf.st_size + (BLCKSZ - 1)) / BLCKSZ;
- if (*totalpages < 1)
- *totalpages = 1;
-
/*
* Create CopyState from FDW options.
*/
@@ -931,10 +942,10 @@ file_acquire_sample_rows(Relation onerel, int elevel,
* Emit some interesting relation info
*/
ereport(elevel,
- (errmsg("\"%s\": scanned %u pages containing %.0f rows; "
+ (errmsg("\"%s\": file contains %.0f rows; "
"%d rows in sample",
RelationGetRelationName(onerel),
- *totalpages, *totalrows, numrows)));
+ *totalrows, numrows)));
return numrows;
}
diff --git a/doc/src/sgml/fdwhandler.sgml b/doc/src/sgml/fdwhandler.sgml
index 8e7525ab59..2c75b80b30 100644
--- a/doc/src/sgml/fdwhandler.sgml
+++ b/doc/src/sgml/fdwhandler.sgml
@@ -279,15 +279,19 @@ EndForeignScan (ForeignScanState *node);
-AcquireSampleRowsFunc
-AnalyzeForeignTable (Relation relation);
+bool
+AnalyzeForeignTable (Relation relation,
+ AcquireSampleRowsFunc *func,
+ BlockNumber *totalpages);
This function is called when is executed on
- a foreign table. If the FDW supports collecting statistics for this
- foreign table, it should return a pointer to a function that will collect
- sample rows from the table. Otherwise, return NULL. If the
- FDW does not support collecting statistics for any tables, the
+ a foreign table. If the FDW can collect statistics for this
+ foreign table, it should return true, and provide a pointer
+ to a function that will collect sample rows from the table in
+ func, plus the estimated size of the table in pages in
+ totalpages. Otherwise, return false.
+ If the FDW does not support collecting statistics for any tables, the
AnalyzeForeignTable pointer can be set to NULL.
@@ -298,18 +302,16 @@ int
AcquireSampleRowsFunc (Relation relation, int elevel,
HeapTuple *rows, int targrows,
double *totalrows,
- double *totaldeadrows,
- BlockNumber *totalpages);
+ double *totaldeadrows);
A random sample of up to targrows rows should be collected
from the table and stored into the caller-provided rows
array. The actual number of rows collected must be returned. In
- addition, store estimates of the total numbers of live rows, dead rows,
- and pages in the table into the output parameters
- totalrows, totaldeadrows, and
- totalpages. These numbers will be recorded in the table's
- pg_class entry for future use.
+ addition, store estimates of the total numbers of live and dead rows in
+ the table into the output parameters totalrows and
+ totaldeadrows. (Set totaldeadrows to zero
+ if the FDW does not have any concept of dead rows.)
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 17abe48f25..ff271644e0 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -84,7 +84,8 @@ static BufferAccessStrategy vac_strategy;
static void do_analyze_rel(Relation onerel, VacuumStmt *vacstmt,
- AcquireSampleRowsFunc acquirefunc, bool inh, int elevel);
+ AcquireSampleRowsFunc acquirefunc, BlockNumber relpages,
+ bool inh, int elevel);
static void BlockSampler_Init(BlockSampler bs, BlockNumber nblocks,
int samplesize);
static bool BlockSampler_HasMore(BlockSampler bs);
@@ -97,8 +98,7 @@ static VacAttrStats *examine_attribute(Relation onerel, int attnum,
Node *index_expr);
static int acquire_sample_rows(Relation onerel, int elevel,
HeapTuple *rows, int targrows,
- double *totalrows, double *totaldeadrows,
- BlockNumber *totalpages);
+ double *totalrows, double *totaldeadrows);
static int compare_rows(const void *a, const void *b);
static int acquire_inherited_sample_rows(Relation onerel, int elevel,
HeapTuple *rows, int targrows,
@@ -117,7 +117,8 @@ analyze_rel(Oid relid, VacuumStmt *vacstmt, BufferAccessStrategy bstrategy)
{
Relation onerel;
int elevel;
- AcquireSampleRowsFunc acquirefunc;
+ AcquireSampleRowsFunc acquirefunc = NULL;
+ BlockNumber relpages = 0;
/* Select logging level */
if (vacstmt->options & VACOPT_VERBOSE)
@@ -182,51 +183,6 @@ analyze_rel(Oid relid, VacuumStmt *vacstmt, BufferAccessStrategy bstrategy)
return;
}
- /*
- * Check that it's a plain table or foreign table; we used to do this
- * in get_rel_oids() but seems safer to check after we've locked the
- * relation.
- */
- if (onerel->rd_rel->relkind == RELKIND_RELATION)
- {
- /* Regular table, so we'll use the regular row acquisition function */
- acquirefunc = acquire_sample_rows;
- }
- else if (onerel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
- {
- /*
- * For a foreign table, call the FDW's hook function to see whether it
- * supports analysis.
- */
- FdwRoutine *fdwroutine;
-
- fdwroutine = GetFdwRoutineByRelId(RelationGetRelid(onerel));
-
- if (fdwroutine->AnalyzeForeignTable != NULL)
- acquirefunc = fdwroutine->AnalyzeForeignTable(onerel);
- else
- acquirefunc = NULL;
-
- if (acquirefunc == NULL)
- {
- ereport(WARNING,
- (errmsg("skipping \"%s\" --- cannot analyze this foreign table",
- RelationGetRelationName(onerel))));
- relation_close(onerel, ShareUpdateExclusiveLock);
- return;
- }
- }
- else
- {
- /* No need for a WARNING if we already complained during VACUUM */
- if (!(vacstmt->options & VACOPT_VACUUM))
- ereport(WARNING,
- (errmsg("skipping \"%s\" --- cannot analyze non-tables or special system tables",
- RelationGetRelationName(onerel))));
- relation_close(onerel, ShareUpdateExclusiveLock);
- return;
- }
-
/*
* Silently ignore tables that are temp tables of other backends ---
* trying to analyze these is rather pointless, since their contents are
@@ -248,6 +204,54 @@ analyze_rel(Oid relid, VacuumStmt *vacstmt, BufferAccessStrategy bstrategy)
return;
}
+ /*
+ * Check that it's a plain table or foreign table; we used to do this
+ * in get_rel_oids() but seems safer to check after we've locked the
+ * relation.
+ */
+ if (onerel->rd_rel->relkind == RELKIND_RELATION)
+ {
+ /* Regular table, so we'll use the regular row acquisition function */
+ acquirefunc = acquire_sample_rows;
+ /* Also get regular table's size */
+ relpages = RelationGetNumberOfBlocks(onerel);
+ }
+ else if (onerel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+ {
+ /*
+ * For a foreign table, call the FDW's hook function to see whether it
+ * supports analysis.
+ */
+ FdwRoutine *fdwroutine;
+ bool ok = false;
+
+ fdwroutine = GetFdwRoutineByRelId(RelationGetRelid(onerel));
+
+ if (fdwroutine->AnalyzeForeignTable != NULL)
+ ok = fdwroutine->AnalyzeForeignTable(onerel,
+ &acquirefunc,
+ &relpages);
+
+ if (!ok)
+ {
+ ereport(WARNING,
+ (errmsg("skipping \"%s\" --- cannot analyze this foreign table",
+ RelationGetRelationName(onerel))));
+ relation_close(onerel, ShareUpdateExclusiveLock);
+ return;
+ }
+ }
+ else
+ {
+ /* No need for a WARNING if we already complained during VACUUM */
+ if (!(vacstmt->options & VACOPT_VACUUM))
+ ereport(WARNING,
+ (errmsg("skipping \"%s\" --- cannot analyze non-tables or special system tables",
+ RelationGetRelationName(onerel))));
+ relation_close(onerel, ShareUpdateExclusiveLock);
+ return;
+ }
+
/*
* OK, let's do it. First let other backends know I'm in ANALYZE.
*/
@@ -258,13 +262,13 @@ analyze_rel(Oid relid, VacuumStmt *vacstmt, BufferAccessStrategy bstrategy)
/*
* Do the normal non-recursive ANALYZE.
*/
- do_analyze_rel(onerel, vacstmt, acquirefunc, false, elevel);
+ do_analyze_rel(onerel, vacstmt, acquirefunc, relpages, false, elevel);
/*
* If there are child tables, do recursive ANALYZE.
*/
if (onerel->rd_rel->relhassubclass)
- do_analyze_rel(onerel, vacstmt, acquirefunc, true, elevel);
+ do_analyze_rel(onerel, vacstmt, acquirefunc, relpages, true, elevel);
/*
* Close source relation now, but keep lock so that no one deletes it
@@ -293,7 +297,8 @@ analyze_rel(Oid relid, VacuumStmt *vacstmt, BufferAccessStrategy bstrategy)
*/
static void
do_analyze_rel(Relation onerel, VacuumStmt *vacstmt,
- AcquireSampleRowsFunc acquirefunc, bool inh, int elevel)
+ AcquireSampleRowsFunc acquirefunc, BlockNumber relpages,
+ bool inh, int elevel)
{
int attr_cnt,
tcnt,
@@ -308,7 +313,6 @@ do_analyze_rel(Relation onerel, VacuumStmt *vacstmt,
numrows;
double totalrows,
totaldeadrows;
- BlockNumber totalpages;
HeapTuple *rows;
PGRUsage ru0;
TimestampTz starttime = 0;
@@ -485,17 +489,13 @@ do_analyze_rel(Relation onerel, VacuumStmt *vacstmt,
*/
rows = (HeapTuple *) palloc(targrows * sizeof(HeapTuple));
if (inh)
- {
numrows = acquire_inherited_sample_rows(onerel, elevel,
rows, targrows,
&totalrows, &totaldeadrows);
- totalpages = 0; /* not needed in this path */
- }
else
numrows = (*acquirefunc) (onerel, elevel,
rows, targrows,
- &totalrows, &totaldeadrows,
- &totalpages);
+ &totalrows, &totaldeadrows);
/*
* Compute the statistics. Temporary results during the calculations for
@@ -576,7 +576,7 @@ do_analyze_rel(Relation onerel, VacuumStmt *vacstmt,
*/
if (!inh)
vac_update_relstats(onerel,
- totalpages,
+ relpages,
totalrows,
visibilitymap_count(onerel),
hasindex,
@@ -1032,7 +1032,6 @@ BlockSampler_Next(BlockSampler bs)
* The actual number of rows selected is returned as the function result.
* We also estimate the total numbers of live and dead rows in the table,
* and return them into *totalrows and *totaldeadrows, respectively.
- * Also, the number of pages in the relation is returned into *totalpages.
*
* The returned list of tuples is in order by physical position in the table.
* (We will rely on this later to derive correlation estimates.)
@@ -1061,8 +1060,7 @@ BlockSampler_Next(BlockSampler bs)
static int
acquire_sample_rows(Relation onerel, int elevel,
HeapTuple *rows, int targrows,
- double *totalrows, double *totaldeadrows,
- BlockNumber *totalpages)
+ double *totalrows, double *totaldeadrows)
{
int numrows = 0; /* # rows now in reservoir */
double samplerows = 0; /* total # rows collected */
@@ -1077,7 +1075,6 @@ acquire_sample_rows(Relation onerel, int elevel,
Assert(targrows > 0);
totalblocks = RelationGetNumberOfBlocks(onerel);
- *totalpages = totalblocks;
/* Need a cutoff xmin for HeapTupleSatisfiesVacuum */
OldestXmin = GetOldestXmin(onerel->rd_rel->relisshared, true);
@@ -1438,7 +1435,7 @@ compare_rows(const void *a, const void *b)
/*
* acquire_inherited_sample_rows -- acquire sample rows from inheritance tree
*
- * This has largely the same API as acquire_sample_rows, except that rows are
+ * This has the same API as acquire_sample_rows, except that rows are
* collected from all inheritance children as well as the specified table.
* We fail and return zero if there are no inheritance children.
*/
@@ -1481,11 +1478,6 @@ acquire_inherited_sample_rows(Relation onerel, int elevel,
/*
* Count the blocks in all the relations. The result could overflow
* BlockNumber, so we use double arithmetic.
- *
- * XXX eventually we will probably want to allow child tables that are
- * foreign tables. Since we can't do RelationGetNumberOfBlocks on a
- * foreign table, it's not very clear what fraction of the total to assign
- * to it here.
*/
rels = (Relation *) palloc(list_length(tableOIDs) * sizeof(Relation));
relblocks = (double *) palloc(list_length(tableOIDs) * sizeof(double));
@@ -1540,7 +1532,6 @@ acquire_inherited_sample_rows(Relation onerel, int elevel,
int childrows;
double trows,
tdrows;
- BlockNumber tpages;
/* Fetch a random sample of the child's rows */
childrows = acquire_sample_rows(childrel,
@@ -1548,8 +1539,7 @@ acquire_inherited_sample_rows(Relation onerel, int elevel,
rows + numrows,
childtargrows,
&trows,
- &tdrows,
- &tpages);
+ &tdrows);
/* We may need to convert from child's rowtype to parent's */
if (childrows > 0 &&
diff --git a/src/include/foreign/fdwapi.h b/src/include/foreign/fdwapi.h
index 6bf3a5e230..0a09c94932 100644
--- a/src/include/foreign/fdwapi.h
+++ b/src/include/foreign/fdwapi.h
@@ -53,11 +53,11 @@ typedef void (*EndForeignScan_function) (ForeignScanState *node);
typedef int (*AcquireSampleRowsFunc) (Relation relation, int elevel,
HeapTuple *rows, int targrows,
double *totalrows,
- double *totaldeadrows,
- BlockNumber *totalpages);
-
-typedef AcquireSampleRowsFunc (*AnalyzeForeignTable_function) (Relation relation);
+ double *totaldeadrows);
+typedef bool (*AnalyzeForeignTable_function) (Relation relation,
+ AcquireSampleRowsFunc *func,
+ BlockNumber *totalpages);
/*
* FdwRoutine is the struct returned by a foreign-data wrapper's handler