Additional mailing lists and information about PostgreSQL can be found
via the PostgreSQL WWW home page at:
- http://postgreSQL.org
+ http://www.postgreSQL.org
There is also an IRC channel on EFNet, channel #PostgreSQL. I use the
unix command irc -c '#PostgreSQL' "$USER" irc.phoenix.net.
3.1) Why does initdb fail?
+ Try these:
* check that you don't have any of the previous version's binaries
in your path
* check to see that you have the proper paths set
message. Why?
It could be a variety of problems, but first check to see that you
- have system V extensions installed in your kernel. PostgreSQL requires
+ have System V extensions installed in your kernel. PostgreSQL requires
kernel support for shared memory and semaphores.
3.4) When I try to start the postmaster, I get IpcMemoryCreate errors. Why?
You need to increase the postmaster's limit on how many concurrent
backend processes it can start.
- In Postgres 6.5 and up, the default limit is 32 processes. You can
+ In PostgreSQL 6.5 and up, the default limit is 32 processes. You can
increase it by restarting the postmaster with a suitable -N value.
With the default configuration you can set -N as large as 1024; if you
need more, increase MAXBACKENDS in include/config.h and rebuild. You
number of semaphores, SEMMNS and SEMMNI, the maximum number of
processes, NPROC, the maximum number of processes per user, MAXUPRC,
and the maximum number of open files, NFILE and NINODE. The reason
- that Postgres has a limit on the number of allowed backend processes
+ that PostgreSQL has a limit on the number of allowed backend processes
is so that you can ensure that your system won't run out of resources.
- In Postgres versions prior to 6.5, the maximum number of backends was
- 64, and changing it required a rebuild after altering the MaxBackendId
- constant in include/storage/sinvaladt.h.
+ In PostgreSQL versions prior to 6.5, the maximum number of backends
+ was 64, and changing it required a rebuild after altering the
+ MaxBackendId constant in include/storage/sinvaladt.h.
3.13) What are the pg_tempNNN.NN files in my database directory?
4.7)How much database disk space is required to store data from a typical
flat file?
- A Postgres database can require about six and a half times the disk
+ A PostgreSQL database can require about six and a half times the disk
space required to store the data in a flat file.
Consider a file of 300,000 lines with two integers on each line. The
4.11) What is an R-tree index?
- An r-tree index is used for indexing spatial data. A hash index can't
+ An R-tree index is used for indexing spatial data. A hash index can't
handle range searches. A B-tree index only handles range searches in a
single dimension. R-tree's can handle multi-dimensional data. For
example, if an R-tree index can be built on an attribute of type
4.16.1) How do I create a serial/auto-incrementing field?
PostgreSQL supports SERIAL data type. It auto-creates a sequence and
- index on the column. For example, this...
+ index on the column. For example, this:
CREATE TABLE person (
id SERIAL,
name TEXT
);
- ...is automatically translated into this...
+ is automatically translated into this:
CREATE SEQUENCE person_id_seq;
CREATE TABLE person (
id INT4 NOT NULL DEFAULT nextval('person_id_seq'),
However, if you need to dump and reload the database, you need to use
pg_dump's -o option or COPY WITH OIDS option to preserve the oids.
- For more details, see Bruce Momjian's chapter on Numbering Rows.
+ Numbering Rows.
4.16.2) How do I get the back the generated SERIAL value after an insert?
via the PostgreSQL WWW home page at:
<BLOCKQUOTE>
-<A HREF="http://postgreSQL.org">http://postgreSQL.org</A>
+<A HREF="http://www.postgreSQL.org">http://www.postgreSQL.org</A>
</BLOCKQUOTE><P>
There is also an IRC channel on EFNet, channel #PostgreSQL.
<H4><A NAME="3.1">3.1</A>) Why does initdb fail?</H4><P>
+Try these:
<UL>
<LI> check that you don't have any of the previous version's binaries in
your path
System Call</I> or core dumped message. Why?</H4><P>
It could be a variety of problems, but first check to see that you
-have system V extensions installed in your kernel. PostgreSQL requires
+have System V extensions installed in your kernel. PostgreSQL requires
kernel support for shared memory and semaphores.<P>
You need to increase the postmaster's limit on how many concurrent backend
processes it can start.<P>
-In Postgres 6.5 and up, the default limit is 32 processes. You can
+In PostgreSQL 6.5 and up, the default limit is 32 processes. You can
increase it by restarting the postmaster with a suitable <I>-N</I>
value. With the default configuration you can set <I>-N</I> as large as
1024; if you need more, increase <SMALL>MAXBACKENDS</SMALL> in
<SMALL>SEMMNS</SMALL> and <SMALL>SEMMNI,</SMALL> the maximum number of
processes, <SMALL>NPROC,</SMALL> the maximum number of processes per
user, <SMALL>MAXUPRC,</SMALL> and the maximum number of open files,
-<SMALL>NFILE</SMALL> and <SMALL>NINODE.</SMALL> The reason that Postgres
+<SMALL>NFILE</SMALL> and <SMALL>NINODE.</SMALL> The reason that PostgreSQL
has a limit on the number of allowed backend processes is so that you
can ensure that your system won't run out of resources.<P>
-In Postgres versions prior to 6.5, the maximum number of backends was
+In PostgreSQL versions prior to 6.5, the maximum number of backends was
64, and changing it required a rebuild after altering the MaxBackendId
constant in <I>include/storage/sinvaladt.h.</I><P>
<H4><A NAME="4.7">4.7</A>)How much database disk space is required to
store data from a typical flat file?<BR></H4><P>
-A Postgres database can require about six and a half times the disk space
+A PostgreSQL database can require about six and a half times the disk space
required to store the data in a flat file.<P>
Consider a file of 300,000 lines with two integers on each line. The
<H4><A NAME="4.11">4.11</A>) What is an R-tree index?</H4><P>
-An r-tree index is used for indexing spatial data. A hash index can't
+An R-tree index is used for indexing spatial data. A hash index can't
handle range searches. A B-tree index only handles range searches in a
single dimension. R-tree's can handle multi-dimensional data. For
example, if an R-tree index can be built on an attribute of type <I>point,</I>
serial/auto-incrementing field?</H4><P>
PostgreSQL supports <SMALL>SERIAL</SMALL> data type. It auto-creates a
-sequence and index on the column. For example, this...
+sequence and index on the column. For example, this:
<PRE>
CREATE TABLE person (
id SERIAL,
name TEXT
);
</PRE>
-...is automatically translated into this...
+is automatically translated into this:
<PRE>
CREATE SEQUENCE person_id_seq;
CREATE TABLE person (
you need to dump and reload the database, you need to use <I>pg_dump's -o</I>
option or <SMALL>COPY WITH OIDS</SMALL> option to preserve the oids.<P>
-For more details, see Bruce Momjian's chapter on
<A HREF="http://www.postgresql.org/docs/aw_pgsql_book">Numbering Rows.</A>
<H4><A NAME="4.16.2">4.16.2</A>) How do I get the back the generated SERIAL value after an insert?</H4><P>
projects / postgresql.git / commitdiff