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Update FAQ.
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doc/FAQ
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doc/FAQ
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The bugs mailing list is available. To subscribe to this list, send
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The bugs mailing list is available. To subscribe to this list, send
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email to pgsql-bugs-request@PostgreSQL.org with a body of:
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email to pgsql-bugs-request@PostgreSQL.org with a body of:
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subscribe
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subscribe
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end
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end
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There is also a developers discussion mailing list available. To
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There is also a developers discussion mailing list available. To
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subscribe to this list, send email to
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subscribe to this list, send email to
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pgsql-hackers-request@PostgreSQL.org with a body of:
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pgsql-hackers-request@PostgreSQL.org with a body of:
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subscribe
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subscribe
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end
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end
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@ -964,19 +962,19 @@ BYTEA bytea variable-length byte array (null-safe)
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4.22) How do I create a column that will default to the current time?
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4.22) How do I create a column that will default to the current time?
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Use now():
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Use now():
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CREATE TABLE test (x int, modtime timestamp DEFAULT now() );
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CREATE TABLE test (x int, modtime timestamp DEFAULT now() );
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4.23) Why are my subqueries using IN so slow?
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4.23) Why are my subqueries using IN so slow?
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Currently, we join subqueries to outer queries by sequentially
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Currently, we join subqueries to outer queries by sequentially
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scanning the result of the subquery for each row of the outer query. A
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scanning the result of the subquery for each row of the outer query. A
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workaround is to replace IN with EXISTS:
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workaround is to replace IN with EXISTS:
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SELECT *
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SELECT *
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FROM tab
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FROM tab
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WHERE col1 IN (SELECT col2 FROM TAB2)
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WHERE col1 IN (SELECT col2 FROM TAB2)
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to:
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to:
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SELECT *
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SELECT *
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FROM tab
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FROM tab
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WHERE EXISTS (SELECT col2 FROM TAB2 WHERE col1 = col2)
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WHERE EXISTS (SELECT col2 FROM TAB2 WHERE col1 = col2)
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1996
doc/src/FAQ/FAQ.html
1996
doc/src/FAQ/FAQ.html
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