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Commitd39a369

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Update FAQ.
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‎doc/FAQ

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Frequently Asked Questions (FAQ) for PostgreSQL
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Last updated:Sat Feb2 16:46:36 EST 2002
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Last updated:Tue Feb12 12:14:52 EST 2002
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Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
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4.15.2) How do I get the value of a SERIAL insert?
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4.15.3) Don't currval() and nextval() lead to a race condition with
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other users?
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4.15.4) Why aren't my sequence numbers reused on transaction abort?
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Why are there gaps in the numbers of my sequence/SERIAL column?
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4.16) What is an OID? What is a TID?
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4.17) What is the meaning of some of the terms used in PostgreSQL?
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4.18) Why do I get the error "ERROR: Memory exhausted in
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No. Currval() returns the current value assigned by your backend, not
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by all users.
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4.15.4) Why aren't my sequence numbers reused on transaction abort? Why are
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there gaps in the numbers of my sequence/SERIAL column?
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To improve concurrency, sequence values are given out to running
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transactions as needed and are now locked until the transaction
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completes. This causes gaps in numbering from aborted transactions.
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4.16) What is an OID? What is a TID?
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OIDs are PostgreSQL's answer to unique row ids. Every row that is

‎doc/src/FAQ/FAQ.html

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alink="#0000ff">
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<H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1>
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<P>Last updated:Sat Feb 2 16:46:36 EST 2002</P>
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<P>Last updated:Tue Feb12 12:14:52 EST 2002</P>
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<P>Current maintainer: Bruce Momjian (<Ahref=
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"mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)<BR>
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<SMALL>SERIAL</SMALL> insert?<BR>
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<Ahref="#4.15.3">4.15.3</A>) Don't<I>currval()</I> and
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<I>nextval()</I> lead to a race condition with other users?<BR>
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<Ahref="#4.15.4">4.15.4</A>) Why aren't my sequence numbers reused
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on transaction abort? Why are there gaps in the numbers of my
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sequence/SERIAL column?<BR>
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<Ahref="#4.16">4.16</A>) What is an<SMALL>OID</SMALL>? What is a
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<SMALL>TID</SMALL>?<BR>
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<Ahref="#4.17">4.17</A>) What is the meaning of some of the terms
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<P>No. Currval() returns the current value assigned by your
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backend, not by all users.</P>
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<H4><Aname="4.15.4">4.15.4</A>) Why aren't my sequence numbers reused
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on transaction abort? Why are there gaps in the numbers of my
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sequence/SERIAL column?</H4>
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<P>To improve concurrency, sequence values are given out to running
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transactions as needed and are now<i>locked</i> until the
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transaction completes. This causes gaps in numbering from aborted
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transactions.
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<H4><Aname="4.16">4.16</A>) What is an<SMALL>OID</SMALL>? What is
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a<SMALL>TID</SMALL>?</H4>
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