Add reloscache and relpgcache cols to pg_class

2 columns reloscache and relpgcache to contain the percentage of files
in cache per relation. May be used by the planner and updated with
ANALYZE OSCACHE; and ANALYZE PGCACHE; (not done yet, see next commits)

Conflicts:
	src/include/catalog/catversion.h

4 files changed, 51 insertions, 21 deletions

diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 7b62818ce4..25338d0ddc 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -1634,6 +1634,26 @@
      </row>
 
      <row>
+      <entry><structfield>reloscache</structfield></entry>
+      <entry><type>float4</type></entry>
+      <entry></entry>
+      <entry>
+       Percentage of the files in OS cache.  This is only an estimate used by
+       the planner.  It is updated by <command>ANALYZE OSCACHE</command>.
+      </entry>
+     </row>
+
+     <row>
+      <entry><structfield>relpgcache</structfield></entry>
+      <entry><type>float4</type></entry>
+      <entry></entry>
+      <entry>
+       Percentage of the files in PostgreSQL cache.  This is only an estimate used by
+       the planner.  It is updated by <command>ANALYZE PGCACHE</command>.
+      </entry>
+     </row>
+
+     <row>
       <entry><structfield>reltoastrelid</structfield></entry>
       <entry><type>oid</type></entry>
       <entry><literal><link linkend="catalog-pg-class"><structname>pg_class</structname></link>.oid</literal></entry>
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index 71c9931834..73ba67bbb7 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -756,6 +756,8 @@ InsertPgClassTuple(Relation pg_class_desc,
 	values[Anum_pg_class_reltablespace - 1] = ObjectIdGetDatum(rd_rel->reltablespace);
 	values[Anum_pg_class_relpages - 1] = Int32GetDatum(rd_rel->relpages);
 	values[Anum_pg_class_reltuples - 1] = Float4GetDatum(rd_rel->reltuples);
+	values[Anum_pg_class_reloscache - 1] = Float4GetDatum(rd_rel->reloscache);
+	values[Anum_pg_class_relpgcache - 1] = Float4GetDatum(rd_rel->relpgcache);
 	values[Anum_pg_class_reltoastrelid - 1] = ObjectIdGetDatum(rd_rel->reltoastrelid);
 	values[Anum_pg_class_reltoastidxid - 1] = ObjectIdGetDatum(rd_rel->reltoastidxid);
 	values[Anum_pg_class_relhasindex - 1] = BoolGetDatum(rd_rel->relhasindex);
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index d7e94ffc12..159096a29a 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -1417,6 +1417,8 @@ formrdesc(const char *relationName, Oid relationReltype,
 
 	relation->rd_rel->relpages = 1;
 	relation->rd_rel->reltuples = 1;
+	relation->rd_rel->reloscache = 0;
+	relation->rd_rel->relpgcache = 0;
 	relation->rd_rel->relkind = RELKIND_RELATION;
 	relation->rd_rel->relhasoids = hasoids;
 	relation->rd_rel->relnatts = (int16) natts;
@@ -2661,6 +2663,8 @@ RelationSetNewRelfilenode(Relation relation, TransactionId freezeXid)
 	{
 		classform->relpages = 0;	/* it's empty until further notice */
 		classform->reltuples = 0;
+		classform->reloscache = 0;
+		classform->relpgcache = 0;
 	}
 	classform->relfrozenxid = freezeXid;
 
diff --git a/src/include/catalog/pg_class.h b/src/include/catalog/pg_class.h
index ffcce3c87c..dc79df51ca 100644
--- a/src/include/catalog/pg_class.h
+++ b/src/include/catalog/pg_class.h
@@ -45,6 +45,8 @@ CATALOG(pg_class,1259) BKI_BOOTSTRAP BKI_ROWTYPE_OID(83) BKI_SCHEMA_MACRO
 	Oid			reltablespace;	/* identifier of table space for relation */
 	int4		relpages;		/* # of blocks (not always up-to-date) */
 	float4		reltuples;		/* # of tuples (not always up-to-date) */
+	float4		reloscache;		/* % of files in OS cache (not always up-to-date) */
+	float4		relpgcache;		/* % of files in PostgreSQL cache (not always up-to-date) */
 	Oid			reltoastrelid;	/* OID of toast table; 0 if none */
 	Oid			reltoastidxid;	/* if toast table, OID of chunk_id index */
 	bool		relhasindex;	/* T if has (or has had) any indexes */
@@ -92,7 +94,7 @@ typedef FormData_pg_class *Form_pg_class;
  * ----------------
  */
 
-#define Natts_pg_class					26
+#define Natts_pg_class					28
 #define Anum_pg_class_relname			1
 #define Anum_pg_class_relnamespace		2
 #define Anum_pg_class_reltype			3
@@ -103,22 +105,24 @@ typedef FormData_pg_class *Form_pg_class;
 #define Anum_pg_class_reltablespace		8
 #define Anum_pg_class_relpages			9
 #define Anum_pg_class_reltuples			10
-#define Anum_pg_class_reltoastrelid		11
-#define Anum_pg_class_reltoastidxid		12
-#define Anum_pg_class_relhasindex		13
-#define Anum_pg_class_relisshared		14
-#define Anum_pg_class_relpersistence	15
-#define Anum_pg_class_relkind			16
-#define Anum_pg_class_relnatts			17
-#define Anum_pg_class_relchecks			18
-#define Anum_pg_class_relhasoids		19
-#define Anum_pg_class_relhaspkey		20
-#define Anum_pg_class_relhasrules		21
-#define Anum_pg_class_relhastriggers	22
-#define Anum_pg_class_relhassubclass	23
-#define Anum_pg_class_relfrozenxid		24
-#define Anum_pg_class_relacl			25
-#define Anum_pg_class_reloptions		26
+#define Anum_pg_class_reloscache		11
+#define Anum_pg_class_relpgcache		12
+#define Anum_pg_class_reltoastrelid		13
+#define Anum_pg_class_reltoastidxid		14
+#define Anum_pg_class_relhasindex		15
+#define Anum_pg_class_relisshared		16
+#define Anum_pg_class_relpersistence	17
+#define Anum_pg_class_relkind			18
+#define Anum_pg_class_relnatts			19
+#define Anum_pg_class_relchecks			20
+#define Anum_pg_class_relhasoids		21
+#define Anum_pg_class_relhaspkey		22
+#define Anum_pg_class_relhasrules		23
+#define Anum_pg_class_relhastriggers	24
+#define Anum_pg_class_relhassubclass	25
+#define Anum_pg_class_relfrozenxid		26
+#define Anum_pg_class_relacl			27
+#define Anum_pg_class_reloptions		28
 
 /* ----------------
  *		initial contents of pg_class
@@ -130,13 +134,13 @@ typedef FormData_pg_class *Form_pg_class;
  */
 
 /* Note: "3" in the relfrozenxid column stands for FirstNormalTransactionId */
-DATA(insert OID = 1247 (  pg_type		PGNSP 71 0 PGUID 0 0 0 0 0 0 0 f f p r 29 0 t f f f f 3 _null_ _null_ ));
+DATA(insert OID = 1247 (  pg_type		PGNSP 71 0 PGUID 0 0 0 0 0 0 0 0 0 f f p r 29 0 t f f f f 3 _null_ _null_ ));
 DESCR("");
-DATA(insert OID = 1249 (  pg_attribute	PGNSP 75 0 PGUID 0 0 0 0 0 0 0 f f p r 20 0 f f f f f 3 _null_ _null_ ));
+DATA(insert OID = 1249 (  pg_attribute	PGNSP 75 0 PGUID 0 0 0 0 0 0 0 0 0 f f p r 20 0 f f f f f 3 _null_ _null_ ));
 DESCR("");
-DATA(insert OID = 1255 (  pg_proc		PGNSP 81 0 PGUID 0 0 0 0 0 0 0 f f p r 25 0 t f f f f 3 _null_ _null_ ));
+DATA(insert OID = 1255 (  pg_proc		PGNSP 81 0 PGUID 0 0 0 0 0 0 0 0 0 f f p r 25 0 t f f f f 3 _null_ _null_ ));
 DESCR("");
-DATA(insert OID = 1259 (  pg_class		PGNSP 83 0 PGUID 0 0 0 0 0 0 0 f f p r 26 0 t f f f f 3 _null_ _null_ ));
+DATA(insert OID = 1259 (  pg_class		PGNSP 83 0 PGUID 0 0 0 0 0 0 0 0 0 f f p r 28 0 t f f f f 3 _null_ _null_ ));
 DESCR("");