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10 | 10 | alink="#0000ff"> |
11 | 11 | <H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1> |
12 | 12 |
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13 | | -<P>Last updated: Mon Jan 31 20:35:58 EST 2005</P> |
| 13 | +<P>Last updated: Mon Jan 31 20:41:21 EST 2005</P> |
14 | 14 |
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15 | 15 | <P>Current maintainer: Bruce Momjian (<Ahref= |
16 | 16 | "mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>) |
@@ -74,8 +74,7 @@ <H2 align="center">Operational Questions</H2> |
74 | 74 | <Ahref="#4.2">4.2</A>) How do I find out what tables, indexes, |
75 | 75 | databases, and users are defined? How do I see the queries used |
76 | 76 | by<I>psql</I> to display them?<BR> |
77 | | -<Ahref="#4.3">4.3</A>) How do you remove a column from a |
78 | | - table, or change its data type?<BR> |
| 77 | +<Ahref="#4.3">4.3</A>) How do you change a column's data type?<BR> |
79 | 78 | <Ahref="#4.4">4.4</A>) What is the maximum size for a row, a |
80 | 79 | table, and a database?<BR> |
81 | 80 | <Ahref="#4.5">4.5</A>) How much database disk space is required |
@@ -645,28 +644,15 @@ <H4><A name="4.2">4.2</A>) How do I find out what tables, indexes, |
645 | 644 | database.</P> |
646 | 645 |
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647 | 646 | <P>There are also system tables beginning with<I>pg_</I> that describe |
648 | | - these too. Use<I>psql -l</I> will list all databases.</P> |
| 647 | + these too.</P> |
| 648 | + |
| 649 | +<P>Use<I>psql -l</I> will list all databases.</P> |
649 | 650 |
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650 | 651 | <P>Also try the file<I>pgsql/src/tutorial/syscat.source</I>. It |
651 | 652 | illustrates many of the<SMALL>SELECT</SMALL>s needed to get |
652 | 653 | information from the database system tables.</P> |
653 | 654 |
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654 | | -<H4><Aname="4.3">4.3</A>) How do you remove a column from a |
655 | | - table, or change its data type?</H4> |
656 | | - |
657 | | -<P><SMALL>DROP COLUMN</SMALL> functionality was added in release 7.3 |
658 | | - with<SMALL>ALTER TABLE DROP COLUMN</SMALL>. In earlier versions, |
659 | | - you can do this:</P> |
660 | | -<PRE> |
661 | | - BEGIN; |
662 | | - LOCK TABLE old_table; |
663 | | - SELECT ... -- select all columns but the one you want to remove |
664 | | - INTO TABLE new_table |
665 | | - FROM old_table; |
666 | | - DROP TABLE old_table; |
667 | | - ALTER TABLE new_table RENAME TO old_table; |
668 | | - COMMIT; |
669 | | -</PRE> |
| 655 | +<H4><Aname="4.3">4.3</A>) How do you change a column's data type?</H4> |
670 | 656 |
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671 | 657 | <P>Changing the data type of a column can be done easily in 8.0 |
672 | 658 | and later with<SMALL>ALTER TABLE ALTER COLUMN TYPE</SMALL>. |
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