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12 | 12 | alink="#0000FF"> |
13 | 13 | <H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1> |
14 | 14 |
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15 | | -<P>Last updated: Tue Sep 4 01:06:12 EDT 2001</P> |
| 15 | +<P>Last updated: Tue Sep 4 01:14:28 EDT 2001</P> |
16 | 16 |
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17 | 17 | <P>Current maintainer: Bruce Momjian (<Ahref= |
18 | 18 | "mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)<BR> |
@@ -1267,12 +1267,18 @@ <H4><A name="4.24">4.24</A>) How do I perform an outer join?<BR> |
1267 | 1267 | WHERE tab1.col1 NOT IN (SELECT tab2.col1 FROM tab2) |
1268 | 1268 | ORDER BY col1 |
1269 | 1269 | </PRE> |
1270 | | -<HR> |
1271 | 1270 |
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1272 | 1271 | <H4><Ahref="#4.25">4.25</A>) How do I perform queries |
1273 | | -using multiple databases?<H4> |
| 1272 | + using multiple databases?<H4> |
| 1273 | + |
| 1274 | +<P>There is no way to query any database except the current one. |
| 1275 | + Because PostgreSQL loads database-specific system catalogs, it is |
| 1276 | + uncertain how a cross-database query should even behave.</P> |
| 1277 | + |
| 1278 | +<P>Of course, a client can make simultaneous connections to |
| 1279 | + different databases and merge the information that way.</P> |
| 1280 | +<HR> |
1274 | 1281 |
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1275 | | -<P> |
1276 | 1282 | <CENTER> |
1277 | 1283 | <H2>Extending PostgreSQL</H2> |
1278 | 1284 | </CENTER> |
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