diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/FAQ/FAQ.html | 60 | ||||
| -rw-r--r-- | doc/src/FAQ/FAQ_DEV.html | 12 | ||||
| -rw-r--r-- | doc/src/FAQ/FAQ_MINGW.html | 4 |
3 files changed, 54 insertions, 22 deletions
diff --git a/doc/src/FAQ/FAQ.html b/doc/src/FAQ/FAQ.html index 71e659db94d..df71e8bf25d 100644 --- a/doc/src/FAQ/FAQ.html +++ b/doc/src/FAQ/FAQ.html @@ -10,7 +10,7 @@ alink="#0000ff"> <H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1> - <P>Last updated: Mon May 30 09:11:03 EDT 2005</P> + <P>Last updated: Fri Sep 16 14:07:22 EDT 2005</P> <P>Current maintainer: Bruce Momjian (<A href= "mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>) @@ -26,7 +26,7 @@ <HR> <H2 align="center">General Questions</H2> - <A href="#1.1">1.1</A>) What is PostgreSQL? How is it pronounced?<BR> + <A href="#1.1">1.1</A>) What is PostgreSQL? How is it pronounced?<BR> <A href="#1.2">1.2</A>) What is the copyright of PostgreSQL?<BR> <A href="#1.3">1.3</A>) What platforms does PostgreSQL support?<BR> <A href="#1.4">1.4</A>) Where can I get PostgreSQL?<BR> @@ -116,7 +116,9 @@ does not exist" errors when accessing temporary tables in PL/PgSQL functions?<BR> <A href="#4.20">4.20</A>) What replication solutions are available?<BR> - + <A href="#4.21">4.21</A>) Why are my table and column names not + recognized in my query?<BR> + <HR> @@ -124,8 +126,10 @@ <H3><A name="1.1">1.1</A>) What is PostgreSQL? How is it pronounced?</H3> - <P>PostgreSQL is pronounced <I>Post-Gres-Q-L</I>, also called just - <I>Postgres</I>.</P> + <P>PostgreSQL is pronounced <I>Post-Gres-Q-L</I>, and is also sometimes + referred to as just <I>Postgres</I>. An audio file is available in + <a href="http://www.postgresql.org/files/postgresql.mp3">MP3 format</a> for + those would like to hear the pronunciation.</P> <P>PostgreSQL is an object-relational database system that has the features of traditional commercial database systems with @@ -231,7 +235,7 @@ <H3><A name="1.7">1.7</A>) What is the latest release?</H3> - <P>The latest release of PostgreSQL is version 8.0.2.</P> + <P>The latest release of PostgreSQL is version 8.0.3.</P> <P>We plan to have a major release every year, with minor releases every few months.</P> @@ -613,6 +617,12 @@ table?</TD><TD>unlimited</TD></TR> <P>The maximum table size and maximum number of columns can be quadrupled by increasing the default block size to 32k.</P> + <P>One limitation is that indexes can not be created on columns + longer than about 2,000 characters. Fortunately, such indexes are + rarely needed. Uniqueness is best guaranteed by a funtion index + of an MD5 hash of the long column, and full text indexing + allows for searching of words within the column.</P> + <H3><A name="4.5">4.5</A>) How much database disk space is required to store data from a typical text file?</H3> @@ -625,23 +635,23 @@ table?</TD><TD>unlimited</TD></TR> The size of the PostgreSQL database file containing this data can be estimated as 6.4 MB:</P> <PRE> - 32 bytes: each row header (approximate) + 28 bytes: each row header (approximate) 24 bytes: one int field and one text field + 4 bytes: pointer on page to tuple ---------------------------------------- - 60 bytes per row + 56 bytes per row The data page size in PostgreSQL is 8192 bytes (8 KB), so: 8192 bytes per page - ------------------- = 136 rows per database page (rounded down) - 60 bytes per row + ------------------- = 146 rows per database page (rounded down) + 56 bytes per row 100000 data rows - -------------------- = 735 database pages (rounded up) - 128 rows per page + -------------------- = 685 database pages (rounded up) + 146 rows per page -735 database pages * 8192 bytes per page = 6,021,120 bytes (6 MB) +685 database pages * 8192 bytes per page = 5,611,520 bytes (5.6 MB) </PRE> <P>Indexes do not require as much overhead, but do contain the data @@ -740,7 +750,12 @@ table?</TD><TD>unlimited</TD></TR> <PRE> CREATE INDEX tabindex ON tab (lower(col)); </PRE> - + <P>If the above index is created as <SMALL>UNIQUE</SMALL>, though + the column can store upper and lowercase characters, it can not have + identical values that differ only in case. To force a particular + case to be stored in the column, use a <SMALL>CHECK</SMALL> + constraint or a trigger.</P> + <H3><A name="4.9">4.9</A>) In a query, how do I detect if a field is <SMALL>NULL</SMALL>? How can I sort on whether a field is <SMALL> NULL</SMALL> or not?</H3> @@ -1000,5 +1015,22 @@ length</TD></TR> <P>There are also commercial and hardware-based replication solutions available supporting a variety of replication models.</P> + + <H3><A name="4.21">4.21</A>) Why are my table and column names not + recognized in my query?</H3> + + <P>The most common cause is the use of double-quotes around table or + column names during table creation. When double-quotes are used, + table and column names (called identifiers) are stored <a + href="http://www.postgresql.org/docs/8.0/static/sql-syntax.html#SQL- + SYNTAX-IDENTIFIERS">case-sensitive</a>, meaning you must use + double-quotes when referencing the names in a query. Some interfaces, + like pgAdmin, automatically double-quote identifiers during table + creation. So, for identifiers to be recognized, you must either: + <UL> + <LI>Avoid double-quoting identifiers when creating tables</LI> + <LI>Use only lowercase characters in identifiers</LI> + <LI>Double-quote identifiers when referencing them in queries</LI> + </UL> </BODY> </HTML> diff --git a/doc/src/FAQ/FAQ_DEV.html b/doc/src/FAQ/FAQ_DEV.html index 9a863498829..69db6aa18c8 100644 --- a/doc/src/FAQ/FAQ_DEV.html +++ b/doc/src/FAQ/FAQ_DEV.html @@ -13,7 +13,7 @@ <H1>Developer's Frequently Asked Questions (FAQ) for PostgreSQL</H1> - <P>Last updated: Sat May 14 12:26:01 EDT 2005</P> + <P>Last updated: Mon Sep 19 21:28:08 EDT 2005</P> <P>Current maintainer: Bruce Momjian (<A href= "mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)<BR> @@ -147,11 +147,11 @@ before starting work. Failure to do so might mean your patch is rejected.</P> - <P>A web site is maintained for patches that are ready to be applied, + <P>A web site is maintained for patches awaiting review, <a href="http://momjian.postgresql.org/cgi-bin/pgpatches"> http://momjian.postgresql.org/cgi-bin/pgpatches</a>, and those that are being kept for the next release, - <a href="http://momjian.postgresql.org/cgi-bin/pgpatches2"> + <a href="http://momjian.postgresql.org/cgi-bin/pgpatches_hold"> http://momjian.postgresql.org/cgi-bin/pgpatches2</a>.</P> <H3><A name="1.5">1.5</A>) I've developed a patch, what next?</H3> @@ -992,9 +992,9 @@ <P>You can also compile with profiling to see what functions are taking execution time. The backend profile files will be deposited - in the <I>pgsql/data/base/dbname</I> directory. The client profile - file will be put in the client's current directory. Linux requires - a compile with <I>-DLINUX_PROFILE</I> for proper profiling.</P> + in the <I>pgsql/data</I> directory. The client profile file will be + put in the client's current directory. Linux requires a compile with + <I>-DLINUX_PROFILE</I> for proper profiling.</P> </BODY> </HTML> diff --git a/doc/src/FAQ/FAQ_MINGW.html b/doc/src/FAQ/FAQ_MINGW.html index 2f8bfc4ced6..e2a6f759f55 100644 --- a/doc/src/FAQ/FAQ_MINGW.html +++ b/doc/src/FAQ/FAQ_MINGW.html @@ -14,8 +14,8 @@ </P> <P>The most recent version of this document can be viewed at <A href= -"http://momjian.postgresql.org/main/writings/pgsql/project/win32.html"> -http://momjian.postgresql.org/main/writings/pgsql/project/win32.html</A>.</P> +"http://www.postgresql.org/docs/faqs.FAQ_MINGW.html"> +http://www.postgresql.org/docs/faqs.FAQ_MINGW.html</A>.</P> <P>The FAQ for running PostgreSQL on native Win32 is at <A href= "http://pginstaller.projects.postgresql.org/FAQ_windows.html"> |