Features

PostgreSQL has most features present in large commercial

DBMS's, like transactions, subselects, triggers, views,and

sophisticated locking. We have some features they don't have,

foreign key referential integrity or outer joins, but are

DBMS's, like transactions, subselects, triggers, views,foreign

key referential integrity, andsophisticated locking. We have

reduce lock contention. We don't have outer joins, but are

working on them for our next release.

Performance

2.1) Are there ODBC drivers for PostgreSQL?

There are two ODBC drivers available,PostODBC and OpenLink ODBC.

There are two ODBC drivers available,PsqlODBC and OpenLink ODBC.

PostODBC is included in the distribution. More information about it

can be gotten from:http://www.insightdist.com/psqlodbc

PsqlODBC is included in the distribution. More information about it

can be gotten from:ftp://ftp.postgresql.org/pub/odbc/index.html

OpenLink ODBC can be gotten from http://www.openlinksw.com. It works

with their standard ODBC client software so you'll have PostgreSQL

commercial-quality support, but a freeware version will always be

available. Questions to postgres95@openlink.co.uk.

See also the ODBC chapter of the Programmer's Guide.

2.2) What tools are available for hooking PostgreSQL to Web pages?

A nice introduction to Database-backed Web pages can be seen at:

4.22) How do I create a column that will default to the current time?

This way always works:

Use now():

CREATE TABLE test (x int, modtime timestamp default now() );

In releases 7.0 and later, you may use:

create table test (x int, modtime timestamp default 'now');

4.23) Why are my subqueries using IN so slow?

Currently, we join subqueries to outer queries by sequential scanning

PostgreSQL has most features present in large commercial DBMS's, like

transactions, subselects, triggers, views,and sophisticated locking.

We have some features they don't have, like user-defined types,

inheritance, rules, and multi-version concurrency control to reduce lock

contention. We don't have foreign key referential integrity or outer

transactions, subselects, triggers, views,foreign key referential

integrity, and sophisticated locking.We have some features they don't

have, like user-defined types,inheritance, rules, and multi-version

concurrency control to reduce lockcontention. We don't have outer

joins, but are working on them for our next release.<BR><BR>

<DT><B>Performance</B>

<H4><ANAME="2.1">2.1</A>) Are there ODBC drivers for PostgreSQL?</H4><P>

There are two ODBC drivers available,PostODBC and OpenLink ODBC.<P>

There are two ODBC drivers available,PsqlODBC and OpenLink ODBC.<P>

PostODBC is included in the distribution. More information about it can

be gotten from:<AHREF="http://www.insightdist.com/psqlodbc">

http://www.insightdist.com/psqlodbc</A><P>

PsqlODBC is included in the distribution. More information about it can

be gotten from:<AHREF="ftp://ftp.postgresql.org/pub/odbc/index.html">

ftp://ftp.postgresql.org/pub/odbc/index.html</A><P>

OpenLink ODBC can be gotten from<AHREF="http://www.openlinksw.com/">

http://www.openlinksw.com</A>. It works with their standard ODBC client

available. Questions to<A

HREF="mailto:postgres95@openlink.co.uk">postgres95@openlink.co.uk</A>.<P>

See also the<AHREF="http://www.postgresql.org/docs/programmer/odbc.htm">

ODBC chapter of the Programmer's Guide</A>.<P>

<H4><ANAME="2.2">2.2</A>) What tools are available for hooking

option or<SMALL>COPY WITH OIDS</SMALL> option to preserve the oids.<P>

For more details, see Bruce Momjian's chapter on

<AHREF="http://www.postgresql.org/docs/aw_pgsql_book/node74.html">Numbering Rows.</A>

<AHREF="http://www.postgresql.org/docs/aw_pgsql_book">Numbering Rows.</A>

<H4><ANAME="4.16.2">4.16.2</A>) How do I get the back the generated SERIAL value after an insert?</H4><P>

Probably the simplest approach is to to retrieve the next SERIAL value from the sequence object with the<I>nextval()</I> function<I>before</I> inserting and then insert it explicitly. Using the example table in<AHREF="#4.16.1">4.16.1</A>, that might look like this: