diff options
Diffstat (limited to 'src/include/commands')
| -rw-r--r-- | src/include/commands/vacuum.h | 32 |
1 files changed, 20 insertions, 12 deletions
diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index b80f0683563..8c58f1ac385 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/commands/vacuum.h,v 1.49 2004/02/12 23:41:04 tgl Exp $ + * $PostgreSQL: pgsql/src/include/commands/vacuum.h,v 1.50 2004/02/13 06:39:49 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -40,18 +40,18 @@ * and must return TRUE to continue analysis, FALSE to skip analysis of this * column. In the TRUE case it must set the compute_stats and minrows fields, * and can optionally set extra_data to pass additional info to compute_stats. + * minrows is its request for the minimum number of sample rows to be gathered + * (but note this request might not be honored, eg if there are fewer rows + * than that in the table). * * The compute_stats routine will be called after sample rows have been * gathered. Aside from this struct, it is passed: - * attnum: attribute number within the supplied tuples - * tupDesc: tuple descriptor for the supplied tuples + * fetchfunc: a function for accessing the column values from the + * sample rows + * samplerows: the number of sample tuples * totalrows: estimated total number of rows in relation - * rows: an array of the sample tuples - * numrows: the number of sample tuples - * Note that the passed attnum and tupDesc could possibly be different from - * what one would expect by looking at the pg_attribute row. It is important - * to use these values for extracting attribute values from the given rows - * (and not for any other purpose). + * The fetchfunc may be called with rownum running from 0 to samplerows-1. + * It returns a Datum and an isNull flag. * * compute_stats should set stats_valid TRUE if it is able to compute * any useful statistics. If it does, the remainder of the struct holds @@ -60,6 +60,11 @@ * be CurrentMemoryContext when compute_stats is called. *---------- */ +typedef struct VacAttrStats *VacAttrStatsP; + +typedef Datum (*AnalyzeAttrFetchFunc) (VacAttrStatsP stats, int rownum, + bool *isNull); + typedef struct VacAttrStats { /* @@ -74,9 +79,10 @@ typedef struct VacAttrStats * These fields must be filled in by the typanalyze routine, * unless it returns FALSE. */ - void (*compute_stats) (struct VacAttrStats *stats, int attnum, - TupleDesc tupDesc, double totalrows, - HeapTuple *rows, int numrows); + void (*compute_stats) (VacAttrStatsP stats, + AnalyzeAttrFetchFunc fetchfunc, + int samplerows, + double totalrows); int minrows; /* Minimum # of rows wanted for stats */ void *extra_data; /* for extra type-specific data */ @@ -100,6 +106,8 @@ typedef struct VacAttrStats * be looked at by type-specific functions. */ int tupattnum; /* attribute number within tuples */ + HeapTuple *rows; /* access info for fetch function */ + TupleDesc tupDesc; } VacAttrStats; |