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Update FAQ_DEV.

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Bruce Momjian
2000-11-04 17:09:24 +00:00
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doc/src/FAQ/FAQ_DEV.html
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@ -38,6 +38,7 @@ tables from the backend code?<BR>
<a href="#10">10</a>) What is elog()?<BR>
<a href="#11">11</a>) What is configure all about?<BR>
<a href="#12">12</a>) How do I add a new port?<BR>
<a href="#13">13</a>) What is CommandCounterIncrement()?<BR>
<BR>
<HR>
@ -481,6 +482,18 @@ appropriate values. Hopefully, there is already locking code in
There is a <I>backend/port</I> directory if you need special files for
your OS.<P>
<H3><a name="13">13</a>) What is CommandCounterIncrement()?</H3><P>
Normally, transactions can not see the rows they modify. This allows <CODE>
UPDATE foo SET x = x + 1</CODE> to work correctly.
<P>
However, there are cases where a transactions needs to see rows affected
in previous parts of the transaction. This is accomplished using a
Command Counter. Incrementing the counter allows transactions to be
broken into pieces so each piece can see rows modified by previous
pieces. <I>CommandCounterIncrement()</I> increments the Command
Counter, creating a new piece of the transaction. <P>
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