@@ -103,15 +103,15 @@ <H2>Operational Questions</H2>
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database?< BR >
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< A href ="#4.7 "> 4.7</ A > ) How much database disk space is required
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to store data from a typical text file?< BR >
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- < A href ="#4.8 "> 4.8</ A > ) How do I find out what indices or
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- operations are defined in the database?< BR >
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+ < A href ="#4.8 "> 4.8</ A > ) How do I find out what tables or
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+ indexes are defined in the database?< BR >
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< A href ="#4.9 "> 4.9</ A > ) My queries are slow or don't make use of
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the indexes. Why?< BR >
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< A href ="#4.10 "> 4.10</ A > ) How do I see how the query optimizer is
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evaluating my query?< BR >
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< A href ="#4.11 "> 4.11</ A > ) What is an R-tree index?< BR >
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- < A href ="#4.12 "> 4.12</ A > ) What is Genetic Query Optimization ?< BR >
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- < A href ="#4.13 "> 4.13</ A > ) How do I do regular expression searches
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+ < A href ="#4.12 "> 4.12</ A > ) What is the Genetic Query Optimizer ?< BR >
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+ < A href ="#4.13 "> 4.13</ A > ) How do I perform regular expression searches
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and case-insensitive regular expression searches?< BR >
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< A href ="#4.14 "> 4.14</ A > ) In a query, how do I detect if a field
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is < SMALL > NULL</ SMALL > ?< BR >
@@ -137,7 +137,7 @@ <H2>Operational Questions</H2>
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default to the current time?< BR >
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< A href ="#4.23 "> 4.23</ A > ) Why are my subqueries using
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< CODE > < SMALL > IN</ SMALL > </ CODE > so slow?< BR >
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- < A href ="#4.24 "> 4.24</ A > ) How do I do an < I > outer</ I > join?< BR >
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+ < A href ="#4.24 "> 4.24</ A > ) How do I perform an < I > outer</ I > join?< BR >
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< CENTER >
@@ -873,8 +873,8 @@ <H4><A name="4.7">4.7</A>) How much database disk space is required
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< P > Indexes do not require as much overhead, but do contain the data
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that is being indexed, so they can be large also.</ P >
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- < H4 > < A name ="4.8 "> 4.8</ A > ) How do I find out what indices or
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- operations are defined in the database?</ H4 >
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+ < H4 > < A name ="4.8 "> 4.8</ A > ) How do I find out what tables or
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+ indexes are defined in the database?</ H4 >
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< P > < I > psql</ I > has a variety of backslash commands to show such
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information. Use \? to see them.</ P >
@@ -943,25 +943,21 @@ <H4><A name="4.11">4.11</A>) What is an R-tree index?</H4>
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practice, extending R-trees requires a bit of work and we don't
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currently have any documentation on how to do it.</ P >
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- < H4 > < A name ="4.12 "> 4.12</ A > ) What is Genetic Query
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- Optimization ?</ H4 >
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+ < H4 > < A name ="4.12 "> 4.12</ A > ) What is the Genetic Query
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+ Optimizer ?</ H4 >
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< P > The < SMALL > GEQO</ SMALL > module speeds query optimization when
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joining many tables by means of a Genetic Algorithm (GA). It allows
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the handling of large join queries through nonexhaustive
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search.</ P >
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- < H4 > < A name ="4.13 "> 4.13</ A > ) How do I do regular expression
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+ < H4 > < A name ="4.13 "> 4.13</ A > ) How do I perform regular expression
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searches and case-insensitive regular expression searches?</ H4 >
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< P > The < I > ~</ I > operator does regular expression matching, and
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- < I > ~*</ I > does case-insensitive regular expression matching. There
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- is no case-insensitive variant of the < SMALL > LIKE</ SMALL > operator,
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- but you can get the effect of case-insensitive < SMALL > LIKE</ SMALL >
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- with this:</ P >
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- < PRE >
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- WHERE lower(textfield) LIKE lower(pattern)
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- </ PRE >
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+ < I > ~*</ I > does case-insensitive regular expression matching. The
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+ case-insensitive variant of < SMALL > LIKE</ SMALL >
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+ is called < SMALL > ILIKE</ SMALL > .</ P >
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< H4 > < A name ="4.14 "> 4.14</ A > ) In a query, how do I detect if a field
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is < SMALL > NULL</ SMALL > ?</ H4 >
@@ -1147,11 +1143,7 @@ <H4><A name="4.19">4.19</A>) Why do I get the error <I>"FATAL:
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Depending on your shell, only one of these may succeed, but it will
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set your process data segment limit much higher and perhaps allow
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the query to complete. This command applies to the current process,
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- and all subprocessesHTML & CSS specifications are available from http://www.w3.org/
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- To learn more about Tidy see http://www.w3.org/People/Raggett/tidy/
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- Please send bug reports to Dave Raggett care of < html-tidy @w3.org >
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- Lobby your company to join W3C, see http://www.w3.org/Consortium
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- created after the command is run. If you are
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+ and all subprocesses created after the command is run. If you are
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having a problem with the < SMALL > SQL</ SMALL > client because the
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backend is returning too much data, try it before starting the
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client.
@@ -1212,7 +1204,7 @@ <H4><A name="4.23">4.23</A>) Why are my subqueries using
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</ PRE >
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We hope to fix this limitation in a future release.
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- < H4 > < A name ="4.24 "> 4.24</ A > ) How do I do an < I > outer</ I > join?< BR >
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+ < H4 > < A name ="4.24 "> 4.24</ A > ) How do I perform an < I > outer</ I > join?< BR >
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</ H4 >
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< P > PostgreSQL 7.1 and later supports outer joins using the SQL
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