Re: extend VacAttrStats to allow stavalues of different types - Mailing list pgsql-patches

Jan Urbański wrote:
> Following the conclusion here:
> http://archives.postgresql.org/pgsql-hackers/2008-05/msg00273.php
> here's a patch that extends VacAttrStats to allow typanalyze functions
> to store statistic values of different types than the underlying column.
>
> The XXX comment can be taken into consideration or just dropped as
> unimportant.

Doh, this time against HEAD, not my branch ...

--
Jan Urbanski
GPG key ID: E583D7D2

ouden estin
*** src/backend/commands/analyze.c
--- src/backend/commands/analyze.c    2008-05-16 00:47:00.000000000 +0200
***************
*** 1321,1330 ****

                  arry = construct_array(stats->stavalues[k],
                                         stats->numvalues[k],
!                                        stats->attr->atttypid,
!                                        stats->attrtype->typlen,
!                                        stats->attrtype->typbyval,
!                                        stats->attrtype->typalign);
                  values[i++] = PointerGetDatum(arry);    /* stavaluesN */
              }
              else
--- 1321,1330 ----

                  arry = construct_array(stats->stavalues[k],
                                         stats->numvalues[k],
!                                        stats->statypid[k],
!                                        stats->statyplen[k],
!                                        stats->statypbyval[k],
!                                        stats->statypalign[k]);
                  values[i++] = PointerGetDatum(arry);    /* stavaluesN */
              }
              else
***************
*** 1854,1859 ****
--- 1854,1867 ----
              stats->numnumbers[0] = num_mcv;
              stats->stavalues[0] = mcv_values;
              stats->numvalues[0] = num_mcv;
+             /*
+              * MCV entries have the same element type as the analyzed
+              * attribute.
+              */
+             stats->statypid[0] = stats->attr->atttypid;
+             stats->statyplen[0] = stats->attrtype->typlen;
+             stats->statypbyval[0] = stats->attrtype->typbyval;
+             stats->statypalign[0] = stats->attrtype->typalign;
          }
      }
      else if (null_cnt > 0)
***************
*** 2197,2202 ****
--- 2205,2218 ----
              stats->numnumbers[slot_idx] = num_mcv;
              stats->stavalues[slot_idx] = mcv_values;
              stats->numvalues[slot_idx] = num_mcv;
+             /*
+              * MCV entries have the same element type as the analyzed
+              * attribute.
+              */
+             stats->statypid[slot_idx] = stats->attr->atttypid;
+             stats->statyplen[slot_idx] = stats->attrtype->typlen;
+             stats->statypbyval[slot_idx] = stats->attrtype->typbyval;
+             stats->statypalign[slot_idx] = stats->attrtype->typalign;
              slot_idx++;
          }

***************
*** 2281,2286 ****
--- 2297,2310 ----
              stats->staop[slot_idx] = mystats->ltopr;
              stats->stavalues[slot_idx] = hist_values;
              stats->numvalues[slot_idx] = num_hist;
+             /*
+              * Histogram entries have the same element type as the analyzed
+              * attribute.
+              */
+             stats->statypid[slot_idx] = stats->attr->atttypid;
+             stats->statyplen[slot_idx] = stats->attrtype->typlen;
+             stats->statypbyval[slot_idx] = stats->attrtype->typbyval;
+             stats->statypalign[slot_idx] = stats->attrtype->typalign;
              slot_idx++;
          }

*** src/include/commands/vacuum.h
--- src/include/commands/vacuum.h    2008-05-16 00:47:09.000000000 +0200
***************
*** 94,99 ****
--- 94,119 ----
      Datum       *stavalues[STATISTIC_NUM_SLOTS];

      /*
+      * These fields describe the stavalues[n] element types. They will
+      * typically be the same as the column's that's underlying the slot, but
+      * sometimes a custom typanalyze function might want to store an array of
+      * something other that the analyzed column's elements. This must be filled
+      * in by the compute_stats routine.
+      *
+      * XXX or maybe fall back on attrtype-> stuff when these are NULL? That way
+      * we won't break other people's custom typanalyze functions. Not sure if
+      * any exist, though.
+      *
+      * Another concern is that typlen, typbyval and typalign are reduntant
+      * given the OID. But the caller is in better position to cache this so
+      * maybe we shouldn't worry about it?
+      */
+     Oid            statypid[STATISTIC_NUM_SLOTS];
+     int2        statyplen[STATISTIC_NUM_SLOTS];
+     bool        statypbyval[STATISTIC_NUM_SLOTS];
+     char        statypalign[STATISTIC_NUM_SLOTS];
+
+     /*
       * These fields are private to the main ANALYZE code and should not be
       * looked at by type-specific functions.
       */