Update DROP COLUMN example to use transactions and rollback-able DROP TABLE>

This commit is contained in:
Bruce Momjian 2002-04-27 03:04:08 +00:00
parent 97b6e3f06f
commit aafe72efb2
2 changed files with 8 additions and 2 deletions

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Frequently Asked Questions (FAQ) for PostgreSQL
Last updated: Thu Apr 18 00:44:51 EDT 2002
Last updated: Fri Apr 26 23:03:46 EDT 2002
Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
@ -637,11 +637,14 @@
4.4) How do you remove a column from a table?
We do not support ALTER TABLE DROP COLUMN, but do this:
BEGIN;
LOCK TABLE old_table;
SELECT ... -- select all columns but the one you want to remove
INTO TABLE new_table
FROM old_table;
DROP TABLE old_table;
ALTER TABLE new_table RENAME TO old_table;
COMMIT;
4.5) What is the maximum size for a row, a table, and a database?

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alink="#0000ff">
<H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1>
<P>Last updated: Thu Apr 18 00:44:51 EDT 2002</P>
<P>Last updated: Fri Apr 26 23:03:46 EDT 2002</P>
<P>Current maintainer: Bruce Momjian (<A href=
"mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)<BR>
@ -827,11 +827,14 @@
<P>We do not support <SMALL>ALTER TABLE DROP COLUMN,</SMALL> but do
this:</P>
<PRE>
BEGIN;
LOCK TABLE old_table;
SELECT ... -- select all columns but the one you want to remove
INTO TABLE new_table
FROM old_table;
DROP TABLE old_table;
ALTER TABLE new_table RENAME TO old_table;
COMMIT;
</PRE>
<H4><A name="4.5">4.5</A>) What is the maximum size for a row, a