Update FAQ.

diff --git a/doc/FAQ b/doc/FAQ
index a4416469962cb1392bd3fd95f2c6f87431dbb8b3..7d821c59c4a622827312531bcd5a76e09a82ce81 100644 (file)
--- a/doc/FAQ
+++ b/doc/FAQ
@@ -1,7 +1,7 @@
 
                 Frequently Asked Questions (FAQ) for PostgreSQL
                                        
-   Last updated: Wed Dec 5 00:41:12 EST 2001
+   Last updated: Fri Jan 4 00:44:42 EST 2002
    
    Current maintainer: Bruce Momjian ([email protected])
    
@@ -58,42 +58,39 @@
    
                            Operational Questions
                                       
-   4.1) Why is the system confused about commas, decimal points, and date
-   formats.
-   4.2) What is the exact difference between binary cursors and normal
-   cursors?
-   4.3) How do I SELECT only the first few rows of a query?
-   4.4) How do I get a list of tables or other things I can see in psql?
-   4.5) How do you remove a column from a table?
-   4.6) What is the maximum size for a row, table, database?
-   4.7) How much database disk space is required to store data from a
+   4.1) What is the difference between binary cursors and normal cursors?
+   4.2) How do I SELECT only the first few rows of a query?
+   4.3) How do I get a list of tables or other things I can see in psql?
+   4.4) How do you remove a column from a table?
+   4.5) What is the maximum size for a row, table, database?
+   4.6) How much database disk space is required to store data from a
    typical text file?
-   4.8) How do I find out what tables or indexes are defined in the
+   4.7) How do I find out what tables or indexes are defined in the
    database?
-   4.9) My queries are slow or don't make use of the indexes. Why?
-   4.10) How do I see how the query optimizer is evaluating my query?
-   4.11) What is an R-tree index?
-   4.12) What is the Genetic Query Optimizer?
-   4.13) How do I perform regular expression searches and
+   4.8) My queries are slow or don't make use of the indexes. Why?
+   4.9) How do I see how the query optimizer is evaluating my query?
+   4.10) What is an R-tree index?
+   4.11) What is the Genetic Query Optimizer?
+   4.12) How do I perform regular expression searches and
    case-insensitive regular expression searches? How do I use an index
    for case-insensitive searches?
-   4.14) In a query, how do I detect if a field is NULL?
-   4.15) What is the difference between the various character types?
-   4.16.1) How do I create a serial/auto-incrementing field?
-   4.16.2) How do I get the value of a SERIAL insert?
-   4.16.3) Don't currval() and nextval() lead to a race condition with
+   4.13) In a query, how do I detect if a field is NULL?
+   4.14) What is the difference between the various character types?
+   4.15.1) How do I create a serial/auto-incrementing field?
+   4.15.2) How do I get the value of a SERIAL insert?
+   4.15.3) Don't currval() and nextval() lead to a race condition with
    other users?
-   4.17) What is an OID? What is a TID?
-   4.18) What is the meaning of some of the terms used in PostgreSQL?
-   4.19) Why do I get the error "ERROR: Memory exhausted in
+   4.16) What is an OID? What is a TID?
+   4.17) What is the meaning of some of the terms used in PostgreSQL?
+   4.18) Why do I get the error "ERROR: Memory exhausted in
    AllocSetAlloc()?"
-   4.20) How do I tell what PostgreSQL version I am running?
-   4.21) My large-object operations get invalid large obj descriptor.
+   4.19) How do I tell what PostgreSQL version I am running?
+   4.20) My large-object operations get invalid large obj descriptor.
    Why?
-   4.22) How do I create a column that will default to the current time?
-   4.23) Why are my subqueries using IN so slow?
-   4.24) How do I perform an outer join?
-   4.25) How do I perform queries using multiple databases?
+   4.21) How do I create a column that will default to the current time?
+   4.22) Why are my subqueries using IN so slow?
+   4.23) How do I perform an outer join?
+   4.24) How do I perform queries using multiple databases?
    
                             Extending PostgreSQL
                                       
@@ -611,19 +608,11 @@
    
                            Operational Questions
                                       
-    4.1) Why is system confused about commas, decimal points, and date formats.
-    
-   Check your locale configuration. PostgreSQL uses the locale setting of
-   the user that ran the postmaster process. There are postgres and psql
-   SET commands to control the date format. Set those accordingly for
-   your operating environment.
-   
-    4.2) What is the exact difference between binary cursors and normal
-    cursors?
+    4.1) What is the difference between binary cursors and normal cursors?
     
    See the DECLARE manual page for a description.
    
-    4.3) How do I SELECT only the first few rows of a query?
+    4.2) How do I SELECT only the first few rows of a query?
     
    See the FETCH manual page, or use SELECT ... LIMIT....
    
@@ -633,7 +622,7 @@
    only the first few records requested, or the entire query may have to
    be evaluated until the desired rows have been generated.
    
-    4.4) How do I get a list of tables or other things I can see in psql?
+    4.3) How do I get a list of tables or other things I can see in psql?
     
    You can read the source code for psql in file
    pgsql/src/bin/psql/describe.c. It contains SQL commands that generate
@@ -641,7 +630,7 @@
    the -E option so it will print out the queries it uses to execute the
    commands you give.
    
-    4.5) How do you remove a column from a table?
+    4.4) How do you remove a column from a table?
     
    We do not support ALTER TABLE DROP COLUMN, but do this:
     SELECT ...  -- select all columns but the one you want to remove
@@ -650,7 +639,7 @@
     DROP TABLE old_table;
     ALTER TABLE new_table RENAME TO old_table;
 
-    4.6) What is the maximum size for a row, table, database?
+    4.5) What is the maximum size for a row, table, database?
     
    These are the limits:
     Maximum size for a database?             unlimited (60GB databases exist)
@@ -672,7 +661,7 @@
    The maximum table size and maximum number of columns can be increased
    if the default block size is increased to 32k.
    
-    4.7) How much database disk space is required to store data from a typical
+    4.6) How much database disk space is required to store data from a typical
     text file?
     
    A PostgreSQL database may need six-and-a-half times the disk space
@@ -702,7 +691,7 @@
    Indexes do not require as much overhead, but do contain the data that
    is being indexed, so they can be large also.
    
-    4.8) How do I find out what tables or indexes are defined in the database?
+    4.7) How do I find out what tables or indexes are defined in the database?
     
    psql has a variety of backslash commands to show such information. Use
    \? to see them.
@@ -711,7 +700,7 @@
    many of the SELECTs needed to get information from the database system
    tables.
    
-    4.9) My queries are slow or don't make use of the indexes. Why?
+    4.8) My queries are slow or don't make use of the indexes. Why?
     
    PostgreSQL does not automatically maintain statistics. VACUUM must be
    run to update the statistics. After statistics are updated, the
@@ -736,11 +725,11 @@
    string. So, to use indices, LIKE searches should not begin with %, and
    ~(regular expression searches) should start with ^.
    
-    4.10) How do I see how the query optimizer is evaluating my query?
+    4.9) How do I see how the query optimizer is evaluating my query?
     
    See the EXPLAIN manual page.
    
-    4.11) What is an R-tree index?
+    4.10) What is an R-tree index?
     
    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
@@ -763,13 +752,13 @@
    extending R-trees requires a bit of work and we don't currently have
    any documentation on how to do it.
    
-    4.12) What is the Genetic Query Optimizer?
+    4.11) What is the Genetic Query Optimizer?
     
    The GEQO module speeds query optimization when joining many tables by
    means of a Genetic Algorithm (GA). It allows the handling of large
    join queries through nonexhaustive search.
    
-    4.13) How do I perform regular expression searches and case-insensitive
+    4.12) How do I perform regular expression searches and case-insensitive
     regular expression searches? How do I use an index for case-insensitive
     searches?
     
@@ -788,11 +777,11 @@
     CREATE INDEX tabindex on tab (lower(col));
 
 
-    4.14) In a query, how do I detect if a field is NULL?
+    4.13) In a query, how do I detect if a field is NULL?
     
    You test the column with IS NULLIS NOT NULL.
    
-    4.15) What is the difference between the various character types?
+    4.14) What is the difference between the various character types?
     
 Type            Internal Name   Notes
 --------------------------------------------------
@@ -817,7 +806,7 @@ BYTEA           bytea           variable-length byte array (null-safe)
    maximum 1 gigabyte. BYTEA is for storing binary data, particularly
    values that include NULL bytes.
    
-    4.16.1) How do I create a serial/auto-incrementing field?
+    4.15.1) How do I create a serial/auto-incrementing field?
     
    PostgreSQL supports a SERIAL data type. It auto-creates a sequence and
    index on the column. For example, this:
@@ -841,11 +830,11 @@ BYTEA           bytea           variable-length byte array (null-safe)
    
    Numbering Rows.
    
-    4.16.2) How do I get the value of a SERIAL insert?
+    4.15.2) How do I get the value of a SERIAL insert?
     
    One approach is to to retrieve the next SERIAL value from the sequence
    object with the nextval() function before inserting and then insert it
-   explicitly. Using the example table in 4.16.1, that might look like
+   explicitly. Using the example table in 4.15.1, that might look like
    this in Perl:
     new_id = output of "SELECT nextval('person_id_seq')"
     INSERT INTO person (id, name) VALUES (new_id, 'Blaise Pascal');
@@ -867,13 +856,13 @@ BYTEA           bytea           variable-length byte array (null-safe)
    oid value is made available via $sth->{pg_oid_status} after
    $sth->execute().
    
-    4.16.3) Don't currval() and nextval() lead to a race condition with other
+    4.15.3) Don't currval() and nextval() lead to a race condition with other
     users?
     
    No. Currval() returns the current value assigned by your backend, not
    by all users.
    
-    4.17) What is an OID? What is a TID?
+    4.16) What is an OID? What is a TID?
     
    OIDs are PostgreSQL's answer to unique row ids. Every row that is
    created in PostgreSQL gets a unique OID. All OIDs generated during
@@ -906,7 +895,7 @@ BYTEA           bytea           variable-length byte array (null-safe)
    values. Tids change after rows are modified or reloaded. They are used
    by index entries to point to physical rows.
    
-    4.18) What is the meaning of some of the terms used in PostgreSQL?
+    4.17) What is the meaning of some of the terms used in PostgreSQL?
     
    Some of the source code and older documentation use terms that have
    more common usage. Here are some:
@@ -923,7 +912,7 @@ BYTEA           bytea           variable-length byte array (null-safe)
    A list of general database terms can be found at:
    http://www.comptechnews.com/~reaster/dbdesign.html
    
-    4.19) Why do I get the error "ERROR: Memory exhausted in AllocSetAlloc()?"
+    4.18) Why do I get the error "ERROR: Memory exhausted in AllocSetAlloc()?"
     
    If you are running a version older than 7.1, an upgrade may fix the
    problem. Also it is possible you have run out of virtual memory on
@@ -939,11 +928,11 @@ BYTEA           bytea           variable-length byte array (null-safe)
    problem with the SQL client because the backend is returning too much
    data, try it before starting the client.
    
-    4.20) How do I tell what PostgreSQL version I am running?
+    4.19) How do I tell what PostgreSQL version I am running?
     
    From psql, type select version();
    
-    4.21) My large-object operations get invalid large obj descriptor. Why?
+    4.20) My large-object operations get invalid large obj descriptor. Why?
     
    You need to put BEGIN WORK and COMMIT around any use of a large object
    handle, that is, surrounding lo_open ... lo_close.
@@ -957,12 +946,12 @@ BYTEA           bytea           variable-length byte array (null-safe)
    If you are using a client interface like ODBC you may need to set
    auto-commit off.
    
-    4.22) How do I create a column that will default to the current time?
+    4.21) How do I create a column that will default to the current time?
     
    Use CURRENT_TIMESTAMP:
 CREATE TABLE test (x int, modtime timestamp DEFAULT CURRENT_TIMESTAMP );
 
-    4.23) Why are my subqueries using IN so slow?
+    4.22) Why are my subqueries using IN so slow?
     
    Currently, we join subqueries to outer queries by sequentially
    scanning the result of the subquery for each row of the outer query. A
@@ -978,7 +967,7 @@ SELECT *
 
    We hope to fix this limitation in a future release.
    
-    4.24) How do I perform an outer join?
+    4.23) How do I perform an outer join?
     
    PostgreSQL 7.1 and later supports outer joins using the SQL standard
    syntax. Here are two examples:
@@ -1008,7 +997,7 @@ SELECT *
     WHERE tab1.col1 NOT IN (SELECT tab2.col1 FROM tab2)
     ORDER BY col1
 
-    4.25) How do I perform queries using multiple databases?
+    4.24) How do I perform queries using multiple databases?
     
    There is no way to query any database except the current one. Because
    PostgreSQL loads database-specific system catalogs, it is uncertain

diff --git a/doc/src/FAQ/FAQ.html b/doc/src/FAQ/FAQ.html
index dd5eb71073ad89a0fc61b9eee9133e9bc7ccd06e..1133ab77d2f6bad6305d6ac01751ab7e41a8f626 100644 (file)
--- a/doc/src/FAQ/FAQ.html
+++ b/doc/src/FAQ/FAQ.html
@@ -11,7 +11,7 @@
   alink="#0000FF">
     Frequently Asked Questions (FAQ) for PostgreSQL
 
-    Last updated: Wed Dec  5 00:41:12 EST 2001
+    Last updated: Fri Jan  4 00:44:42 EST 2002
 
     Current maintainer: Bruce Momjian (
     "mailto:[email protected]">[email protected])
@@ -89,57 +89,55 @@
     
       Operational Questions
     
-    4.1) Why is the system confused about commas,
-    decimal points, and date formats.
-     4.2) What is the exact difference between
+     4.1) What is the difference between
     binary cursors and normal cursors?
-     3">4.3) How do I SELECT only the
+     2">4.2) How do I SELECT only the
     first few rows of a query?
-     4">4.4) How do I get a list of tables or other
+     3">4.3) How do I get a list of tables or other
     things I can see in psql?
-     5">4.5) How do you remove a column from a
+     4">4.4) How do you remove a column from a
     table?
-     6">4.6) What is the maximum size for a row, table,
+     5">4.5) What is the maximum size for a row, table,
     database?
-     7">4.7) How much database disk space is required
+     6">4.6) How much database disk space is required
     to store data from a typical text file?
-     8">4.8) How do I find out what tables or indexes
+     7">4.7) How do I find out what tables or indexes
     are defined in the database?
-     9">4.9) My queries are slow or don't make use of
+     8">4.8) My queries are slow or don't make use of
     the indexes. Why?
-     10">4.10) How do I see how the query optimizer is
+     9">4.9) How do I see how the query optimizer is
     evaluating my query?
-     1">4.11) What is an R-tree index?
-     2">4.12) What is the Genetic Query Optimizer?
-     3">4.13) How do I perform regular expression
+     0">4.10) What is an R-tree index?
+     1">4.11) What is the Genetic Query Optimizer?
+     2">4.12) How do I perform regular expression
     searches and case-insensitive regular expression searches? How do I
     use an index for case-insensitive searches?
-     4">4.14) In a query, how do I detect if a field
+     3">4.13) In a query, how do I detect if a field
     is NULL?
-     5">4.15) What is the difference between the
+     4">4.14) What is the difference between the
     various character types?
-     6.1">4.16.1) How do I create a
+     5.1">4.15.1) How do I create a
     serial/auto-incrementing field?
-     6.2">4.16.2) How do I get the value of a
+     5.2">4.15.2) How do I get the value of a
     SERIAL insert?
-     6.3">4.16.3) Don't currval() and
+     5.3">4.15.3) Don't currval() and
     nextval() lead to a race condition with other users?
-     7">4.17) What is an OID? What is a
+     6">4.16) What is an OID? What is a
     TID?
-     8">4.18) What is the meaning of some of the terms
+     7">4.17) What is the meaning of some of the terms
     used in PostgreSQL?
-     9">4.19) Why do I get the error "ERROR: 
+     8">4.18) Why do I get the error "ERROR: 
      Memory exhausted in AllocSetAlloc()?"
-     20">4.20) How do I tell what PostgreSQL version I
+     19">4.19) How do I tell what PostgreSQL version I
     am running? 
-     1">4.21) My large-object operations get
+     0">4.20) My large-object operations get
     invalid large obj descriptor. Why?
-     2">4.22) How do I create a column that will
+     1">4.21) How do I create a column that will
     default to the current time?
-     3">4.23) Why are my subqueries using
+     2">4.22) Why are my subqueries using
     IN so slow?
-     4">4.24) How do I perform an outer join?
-     5">4.25) How do I perform queries using multiple databases?
+     3">4.23) How do I perform an outer join?
+     4">4.24) How do I perform queries using multiple databases?
      
 
     
@@ -788,22 +786,13 @@
       Operational Questions
     
 
-    4.1) Why is system confused about commas,
-    decimal points, and date formats.
-
-    Check your locale configuration. PostgreSQL uses the locale
-    setting of the user that ran the postmaster process. There
-    are postgres and psql SET commands to control the
-    date format. Set those accordingly for your operating
-    environment.
-
-    4.2) What is the exact difference between
+    4.1) What is the difference between
     binary cursors and normal cursors?
 
     See the DECLARE manual page for a
     description.
 
-    3">4.3) How do I SELECT only the
+    2">4.2) How do I SELECT only the
     first few rows of a query?
 
     See the FETCH manual page, or use
@@ -816,7 +805,7 @@
     records requested, or the entire query may have to be evaluated
     until the desired rows have been generated.
 
-    4">4.4) How do I get a list of tables or other
+    3">4.3) How do I get a list of tables or other
     things I can see in psql?
     
 
@@ -827,7 +816,7 @@
     -E option so it will print out the queries it uses to
     execute the commands you give.
 
-    5">4.5) How do you remove a column from a
+    4">4.4) How do you remove a column from a
     table?
 
     We do not support ALTER TABLE DROP COLUMN, but do
@@ -840,7 +829,7 @@
     ALTER TABLE new_table RENAME TO old_table;
 
 
-    6">4.6) What is the maximum size for a row,
+    5">4.5) What is the maximum size for a row,
     table, database?
 
     These are the limits:
@@ -864,7 +853,7 @@
     The maximum table size and maximum number of columns can be
     increased if the default block size is increased to 32k.
 
-    7">4.7) How much database disk space is required
+    6">4.6) How much database disk space is required
     to store data from a typical text file?
     
 
@@ -897,7 +886,7 @@
     Indexes do not require as much overhead, but do contain the data
     that is being indexed, so they can be large also.
 
-    8">4.8) How do I find out what tables or indexes
+    7">4.7) How do I find out what tables or indexes
     are defined in the database?
 
     psql has a variety of backslash commands to show such
@@ -907,7 +896,7 @@
     illustrates many of the SELECTs needed to get
     information from the database system tables.
 
-    9">4.9) My queries are slow or don't make use of
+    8">4.8) My queries are slow or don't make use of
     the indexes. Why?
 
     PostgreSQL does not automatically maintain statistics.
@@ -937,12 +926,12 @@
     ~(regular expression searches) should start with
     ^.
 
-    10">4.10) How do I see how the query optimizer
+    9">4.9) How do I see how the query optimizer
     is evaluating my query?
 
     See the EXPLAIN manual page.
 
-    1">4.11) What is an R-tree index?
+    0">4.10) What is an R-tree index?
 
     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
@@ -967,7 +956,7 @@
     practice, extending R-trees requires a bit of work and we don't
     currently have any documentation on how to do it.
 
-    2">4.12) What is the Genetic Query
+    1">4.11) What is the Genetic Query
     Optimizer?
 
     The GEQO module speeds query optimization when
@@ -975,7 +964,7 @@
     the handling of large join queries through nonexhaustive
     search.
 
-    3">4.13) How do I perform regular expression
+    2">4.12) How do I perform regular expression
     searches and case-insensitive regular expression searches?  How do I
     use an index for case-insensitive searches?
 
@@ -999,12 +988,12 @@
     CREATE INDEX tabindex on tab (lower(col));
     
 
-    4">4.14) In a query, how do I detect if a field
+    3">4.13) In a query, how do I detect if a field
     is NULL?
 
     You test the column with IS NULLIS NOT NULL.
 
-    5">4.15) What is the difference between the
+    4">4.14) What is the difference between the
     various character types?
 
 Type            Internal Name   Notes
@@ -1034,7 +1023,7 @@ BYTEA           bytea           variable-length byte array (null-safe)
     binary data, particularly values that include NULL
     bytes.
     
-    6.1">4.16.1) How do I create a
+    5.1">4.15.1) How do I create a
     serial/auto-incrementing field?
 
     PostgreSQL supports a SERIAL data type. It
@@ -1064,13 +1053,13 @@ BYTEA           bytea           variable-length byte array (null-safe)
     Numbering
     Rows.
 
-    6.2">4.16.2) How do I get the value of a
+    5.2">4.15.2) How do I get the value of a
     SERIAL insert?
 
     One approach is to to retrieve the next SERIAL
     value from the sequence object with the nextval() function
     before inserting and then insert it explicitly. Using the
-    example table in 6.1">4.16.1, that might look like
+    example table in 5.1">4.15.1, that might look like
     this in Perl:
 
     new_id = output of "SELECT nextval('person_id_seq')"
@@ -1091,20 +1080,20 @@ BYTEA           bytea           variable-length byte array (null-safe)
     INSERT INTO person (name) VALUES ('Blaise Pascal');
     new_id = output of "SELECT currval('person_id_seq')";
 
-    Finally, you could use the 7">OID
+    Finally, you could use the 6">OID
     returned from the INSERT statement to look up the
     default value, though this is probably the least portable approach.
     In Perl, using DBI with Edmund Mergl's DBD::Pg module, the oid
     value is made available via $sth->{pg_oid_status} after
     $sth->execute(). 
 
-    6.3">4.16.3) Don't currval() and
+    5.3">4.15.3) Don't currval() and
     nextval() lead to a race condition with other users?
 
     No. Currval() returns the current value assigned by your
     backend, not by all users.
 
-    7">4.17) What is an OID? What is
+    6">4.16) What is an OID? What is
     a TID?
 
     OIDs are PostgreSQL's answer to unique row ids.
@@ -1149,7 +1138,7 @@ BYTEA           bytea           variable-length byte array (null-safe)
     or reloaded. They are used by index entries to point to physical
     rows.
 
-    8">4.18) What is the meaning of some of the
+    7">4.17) What is the meaning of some of the
     terms used in PostgreSQL?
 
     Some of the source code and older documentation use terms that
@@ -1178,7 +1167,7 @@ BYTEA           bytea           variable-length byte array (null-safe)
     A list of general database terms can be found at: 
     "http://www.comptechnews.com/~reaster/dbdesign.html">http://www.comptechnews.com/~reaster/dbdesign.html
 
-    9">4.19) Why do I get the error "ERROR: 
+    8">4.18) Why do I get the error "ERROR: 
      Memory exhausted in AllocSetAlloc()?"
     
 
@@ -1198,13 +1187,13 @@ BYTEA           bytea           variable-length byte array (null-safe)
     backend is returning too much data, try it before starting the
     client. 
 
-    20">4.20) How do I tell what PostgreSQL version
+    19">4.19) How do I tell what PostgreSQL version
     I am running?
     
 
     From psql, type select version();
 
-    1">4.21) My large-object operations get
+    0">4.20) My large-object operations get
     invalid large obj descriptor. Why?
     
 
@@ -1221,7 +1210,7 @@ BYTEA           bytea           variable-length byte array (null-safe)
     If you are using a client interface like ODBC you
     may need to set auto-commit off.
 
-    2">4.22) How do I create a column that will
+    1">4.21) How do I create a column that will
     default to the current time?
     
 
@@ -1231,7 +1220,7 @@ BYTEA           bytea           variable-length byte array (null-safe)
 
 
 
-    3">4.23) Why are my subqueries using
+    2">4.22) Why are my subqueries using
     IN so slow?
     
 
@@ -1254,7 +1243,7 @@ BYTEA           bytea           variable-length byte array (null-safe)
 
     We hope to fix this limitation in a future release. 
 
-    4">4.24) How do I perform an outer join?
+    3">4.23) How do I perform an outer join?
     
 
     PostgreSQL 7.1 and later supports outer joins using the SQL
@@ -1295,7 +1284,7 @@ BYTEA           bytea           variable-length byte array (null-safe)
     ORDER BY col1
 
 
-    5">4.25) How do I perform queries
+    4">4.24) How do I perform queries
     using multiple databases?
 
     There is no way to query any database except the current one.