Refactor relation_needs_vacanalyze().

This commit adds an early return to this function, allowing us to
remove a level of indentation on a decent chunk of code.  This is
preparatory work for follow-up commits that will add a new system
view to show tables' autovacuum scores.

Reviewed-by: Sami Imseih <samimseih@gmail.com>
Discussion: https://postgr.es/m/CAA5RZ0s4xjMrB-VAnLccC7kY8d0-4806-Lsac-czJsdA1LXtAw%40mail.gmail.com

diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 6694f4852168fee280035f1bd4d843f604d91ffc..590e4c8e44c14d3f392e302ebe3a8f24e5c4064a 100644 (file)
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -3123,6 +3123,11 @@ relation_needs_vacanalyze(Oid relid,
        MultiXactId relminmxid;
        MultiXactId multiForceLimit;
 
+       float4          pcnt_unfrozen = 1;
+       float4          reltuples = classForm->reltuples;
+       int32           relpages = classForm->relpages;
+       int32           relallfrozen = classForm->relallfrozen;
+
        Assert(classForm != NULL);
        Assert(OidIsValid(relid));
 
@@ -3263,94 +3268,88 @@ relation_needs_vacanalyze(Oid relid,
         * vacuuming only, so don't vacuum (or analyze) anything that's not being
         * forced.
         */
-       if (tabentry && AutoVacuumingActive())
-       {
-               float4          pcnt_unfrozen = 1;
-               float4          reltuples = classForm->reltuples;
-               int32           relpages = classForm->relpages;
-               int32           relallfrozen = classForm->relallfrozen;
+       if (!tabentry || !AutoVacuumingActive())
+               return;
 
-               vactuples = tabentry->dead_tuples;
-               instuples = tabentry->ins_since_vacuum;
-               anltuples = tabentry->mod_since_analyze;
+       vactuples = tabentry->dead_tuples;
+       instuples = tabentry->ins_since_vacuum;
+       anltuples = tabentry->mod_since_analyze;
 
-               /* If the table hasn't yet been vacuumed, take reltuples as zero */
-               if (reltuples < 0)
-                       reltuples = 0;
+       /* If the table hasn't yet been vacuumed, take reltuples as zero */
+       if (reltuples < 0)
+               reltuples = 0;
 
+       /*
+        * If we have data for relallfrozen, calculate the unfrozen percentage of
+        * the table to modify insert scale factor. This helps us decide whether
+        * or not to vacuum an insert-heavy table based on the number of inserts
+        * to the more "active" part of the table.
+        */
+       if (relpages > 0 && relallfrozen > 0)
+       {
                /*
-                * If we have data for relallfrozen, calculate the unfrozen percentage
-                * of the table to modify insert scale factor. This helps us decide
-                * whether or not to vacuum an insert-heavy table based on the number
-                * of inserts to the more "active" part of the table.
+                * It could be the stats were updated manually and relallfrozen >
+                * relpages. Clamp relallfrozen to relpages to avoid nonsensical
+                * calculations.
                 */
-               if (relpages > 0 && relallfrozen > 0)
-               {
-                       /*
-                        * It could be the stats were updated manually and relallfrozen >
-                        * relpages. Clamp relallfrozen to relpages to avoid nonsensical
-                        * calculations.
-                        */
-                       relallfrozen = Min(relallfrozen, relpages);
-                       pcnt_unfrozen = 1 - ((float4) relallfrozen / relpages);
-               }
+               relallfrozen = Min(relallfrozen, relpages);
+               pcnt_unfrozen = 1 - ((float4) relallfrozen / relpages);
+       }
 
-               vacthresh = (float4) vac_base_thresh + vac_scale_factor * reltuples;
-               if (vac_max_thresh >= 0 && vacthresh > (float4) vac_max_thresh)
-                       vacthresh = (float4) vac_max_thresh;
+       vacthresh = (float4) vac_base_thresh + vac_scale_factor * reltuples;
+       if (vac_max_thresh >= 0 && vacthresh > (float4) vac_max_thresh)
+               vacthresh = (float4) vac_max_thresh;
 
-               vacinsthresh = (float4) vac_ins_base_thresh +
-                       vac_ins_scale_factor * reltuples * pcnt_unfrozen;
-               anlthresh = (float4) anl_base_thresh + anl_scale_factor * reltuples;
+       vacinsthresh = (float4) vac_ins_base_thresh +
+               vac_ins_scale_factor * reltuples * pcnt_unfrozen;
+       anlthresh = (float4) anl_base_thresh + anl_scale_factor * reltuples;
 
-               /*
-                * Determine if this table needs vacuum, and update the score if it
-                * does.
-                */
-               if (vactuples > vacthresh)
-               {
-                       scores->vac = (double) vactuples / Max(vacthresh, 1);
-                       scores->vac *= autovacuum_vacuum_score_weight;
-                       scores->max = Max(scores->max, scores->vac);
-                       *dovacuum = true;
-               }
-
-               if (vac_ins_base_thresh >= 0 && instuples > vacinsthresh)
-               {
-                       scores->vac_ins = (double) instuples / Max(vacinsthresh, 1);
-                       scores->vac_ins *= autovacuum_vacuum_insert_score_weight;
-                       scores->max = Max(scores->max, scores->vac_ins);
-                       *dovacuum = true;
-               }
+       /*
+        * Determine if this table needs vacuum, and update the score if it does.
+        */
+       if (vactuples > vacthresh)
+       {
+               scores->vac = (double) vactuples / Max(vacthresh, 1);
+               scores->vac *= autovacuum_vacuum_score_weight;
+               scores->max = Max(scores->max, scores->vac);
+               *dovacuum = true;
+       }
 
-               /*
-                * Determine if this table needs analyze, and update the score if it
-                * does.  Note that we don't analyze TOAST tables and pg_statistic.
-                */
-               if (anltuples > anlthresh &&
-                       relid != StatisticRelationId &&
-                       classForm->relkind != RELKIND_TOASTVALUE)
-               {
-                       scores->anl = (double) anltuples / Max(anlthresh, 1);
-                       scores->anl *= autovacuum_analyze_score_weight;
-                       scores->max = Max(scores->max, scores->anl);
-                       *doanalyze = true;
-               }
+       if (vac_ins_base_thresh >= 0 && instuples > vacinsthresh)
+       {
+               scores->vac_ins = (double) instuples / Max(vacinsthresh, 1);
+               scores->vac_ins *= autovacuum_vacuum_insert_score_weight;
+               scores->max = Max(scores->max, scores->vac_ins);
+               *dovacuum = true;
+       }
 
-               if (vac_ins_base_thresh >= 0)
-                       elog(DEBUG3, "%s: vac: %.0f (thresh %.0f, score %.2f), ins: %.0f (thresh %.0f, score %.2f), anl: %.0f (thresh %.0f, score %.2f), xid score: %.2f, mxid score: %.2f",
-                                NameStr(classForm->relname),
-                                vactuples, vacthresh, scores->vac,
-                                instuples, vacinsthresh, scores->vac_ins,
-                                anltuples, anlthresh, scores->anl,
-                                scores->xid, scores->mxid);
-               else
-                       elog(DEBUG3, "%s: vac: %.0f (thresh %.0f, score %.2f), ins: (disabled), anl: %.0f (thresh %.0f, score %.2f), xid score: %.2f, mxid score: %.2f",
-                                NameStr(classForm->relname),
-                                vactuples, vacthresh, scores->vac,
-                                anltuples, anlthresh, scores->anl,
-                                scores->xid, scores->mxid);
+       /*
+        * Determine if this table needs analyze, and update the score if it does.
+        * Note that we don't analyze TOAST tables and pg_statistic.
+        */
+       if (anltuples > anlthresh &&
+               relid != StatisticRelationId &&
+               classForm->relkind != RELKIND_TOASTVALUE)
+       {
+               scores->anl = (double) anltuples / Max(anlthresh, 1);
+               scores->anl *= autovacuum_analyze_score_weight;
+               scores->max = Max(scores->max, scores->anl);
+               *doanalyze = true;
        }
+
+       if (vac_ins_base_thresh >= 0)
+               elog(DEBUG3, "%s: vac: %.0f (thresh %.0f, score %.2f), ins: %.0f (thresh %.0f, score %.2f), anl: %.0f (thresh %.0f, score %.2f), xid score: %.2f, mxid score: %.2f",
+                        NameStr(classForm->relname),
+                        vactuples, vacthresh, scores->vac,
+                        instuples, vacinsthresh, scores->vac_ins,
+                        anltuples, anlthresh, scores->anl,
+                        scores->xid, scores->mxid);
+       else
+               elog(DEBUG3, "%s: vac: %.0f (thresh %.0f, score %.2f), ins: (disabled), anl: %.0f (thresh %.0f, score %.2f), xid score: %.2f, mxid score: %.2f",
+                        NameStr(classForm->relname),
+                        vactuples, vacthresh, scores->vac,
+                        anltuples, anlthresh, scores->anl,
+                        scores->xid, scores->mxid);
 }
 
 /*