diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/perform.sgml | 8 | ||||
| -rw-r--r-- | doc/src/sgml/planstats.sgml | 4 |
2 files changed, 6 insertions, 6 deletions
diff --git a/doc/src/sgml/perform.sgml b/doc/src/sgml/perform.sgml index b69813cedba..014a91b1e9e 100644 --- a/doc/src/sgml/perform.sgml +++ b/doc/src/sgml/perform.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/perform.sgml,v 1.82 2010/06/28 22:46:11 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/perform.sgml,v 1.83 2010/07/13 20:57:19 tgl Exp $ --> <chapter id="performance-tips"> <title>Performance Tips</title> @@ -316,7 +316,7 @@ WHERE t1.unique1 < 100 AND t1.unique2 = t2.unique2; -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..2.37 rows=106 width=0) Index Cond: (unique1 < 100) -> Index Scan using tenk2_unique2 on tenk2 t2 (cost=0.00..3.01 rows=1 width=244) - Index Cond: (t2.unique2 = t1.unique2) + Index Cond: (unique2 = t1.unique2) </programlisting> </para> @@ -329,7 +329,7 @@ WHERE t1.unique1 < 100 AND t1.unique2 = t2.unique2; so it doesn't affect the row count of the outer scan. For the inner (lower) scan, the <literal>unique2</> value of the current outer-scan row is plugged into the inner index scan to produce an index condition like - <literal>t2.unique2 = <replaceable>constant</replaceable></literal>. + <literal>unique2 = <replaceable>constant</replaceable></literal>. So we get the same inner-scan plan and costs that we'd get from, say, <literal>EXPLAIN SELECT * FROM tenk2 WHERE unique2 = 42</literal>. The costs of the loop node are then set on the basis of the cost of the outer @@ -405,7 +405,7 @@ WHERE t1.unique1 < 100 AND t1.unique2 = t2.unique2; -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..2.37 rows=106 width=0) (actual time=0.546..0.546 rows=100 loops=1) Index Cond: (unique1 < 100) -> Index Scan using tenk2_unique2 on tenk2 t2 (cost=0.00..3.01 rows=1 width=244) (actual time=0.067..0.078 rows=1 loops=100) - Index Cond: (t2.unique2 = t1.unique2) + Index Cond: (unique2 = t1.unique2) Total runtime: 14.452 ms </screen> diff --git a/doc/src/sgml/planstats.sgml b/doc/src/sgml/planstats.sgml index 1d6e52afd9a..7d9cb399784 100644 --- a/doc/src/sgml/planstats.sgml +++ b/doc/src/sgml/planstats.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/planstats.sgml,v 1.9 2007/12/28 21:03:31 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/planstats.sgml,v 1.10 2010/07/13 20:57:19 tgl Exp $ --> <chapter id="planner-stats-details"> <title>How the Planner Uses Statistics</title> @@ -353,7 +353,7 @@ WHERE t1.unique1 < 50 AND t1.unique2 = t2.unique2; -> Bitmap Index Scan on tenk1_unique1 (cost=0.00..4.63 rows=50 width=0) Index Cond: (unique1 < 50) -> Index Scan using tenk2_unique2 on tenk2 t2 (cost=0.00..6.27 rows=1 width=244) - Index Cond: (t2.unique2 = t1.unique2) + Index Cond: (unique2 = t1.unique2) </programlisting> The restriction on <structname>tenk1</structname>, |