Remove FAQ about database terms.
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Bruce Momjian
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doc/FAQ
119
doc/FAQ
@ -1,7 +1,7 @@
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Frequently Asked Questions (FAQ) for PostgreSQL
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Last updated: Mon Jan 31 20:41:21 EST 2005
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Last updated: Mon Jan 31 21:31:39 EST 2005
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Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
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@ -68,19 +68,18 @@
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4.11.3) Why aren't my sequence numbers reused on transaction abort?
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Why are there gaps in the numbering of my sequence/SERIAL column?
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4.12) What is an OID? What is a TID?
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4.13) What is the meaning of some of the terms used in PostgreSQL?
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4.14) Why do I get the error "ERROR: Memory exhausted in
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4.13) Why do I get the error "ERROR: Memory exhausted in
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AllocSetAlloc()"?
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4.15) How do I tell what PostgreSQL version I am running?
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4.16) Why does my large-object operations get "invalid large obj
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4.14) How do I tell what PostgreSQL version I am running?
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4.15) Why does my large-object operations get "invalid large obj
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descriptor"?
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4.17) How do I create a column that will default to the current time?
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4.18) How do I perform an outer join?
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4.19) How do I perform queries using multiple databases?
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4.20) How do I return multiple rows or columns from a function?
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4.21) Why can't I reliably create/drop temporary tables in PL/PgSQL
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4.16) How do I create a column that will default to the current time?
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4.17) How do I perform an outer join?
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4.18) How do I perform queries using multiple databases?
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4.19) How do I return multiple rows or columns from a function?
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4.20) Why can't I reliably create/drop temporary tables in PL/PgSQL
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functions?
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4.22) What encryption options are available?
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4.21) What encryption options are available?
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Extending PostgreSQL
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@ -394,6 +393,7 @@
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properly. First, by running configure with the --enable-cassert
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option, many assert()s monitor the progress of the backend and halt
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the program when something unexpected occurs.
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The postmaster has a -d option that allows even more detailed
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information to be reported. The -d option takes a number that
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specifies the debug level. Be warned that high debug level values
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@ -517,14 +517,16 @@
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4.4) What is the maximum size for a row, a table, and a database?
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These are the limits:
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Maximum size for a database? unlimited (32 TB databases exist)
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Maximum size for a table? 32 TB
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Maximum size for a row? 1.6TB
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Maximum size for a field? 1 GB
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Maximum number of rows in a table? unlimited
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Maximum number of columns in a table? 250-1600 depending on column types
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Maximum number of indexes on a table? unlimited
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Maximum size for a database? unlimited (32 TB databases exist)
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Maximum size for a table? 32 TB
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Maximum size for a row? 1.6TB
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Maximum size for a field? 1 GB
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Maximum number of rows in a table? unlimited
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Maximum number of columns in a table? 250-1600 depending on column
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types
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Maximum number of indexes on a table? unlimited
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Of course, these are not actually unlimited, but limited to available
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disk space and memory/swap space. Performance may suffer when these
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values get unusually large.
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@ -611,15 +613,15 @@
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* The search string can not start with a character class, e.g.
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[a-e].
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* Case-insensitive searches such as ILIKE and ~* do not utilize
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indexes. Instead, use functional indexes, which are described in
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section 4.10.
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indexes. Instead, use expression indexes, which are described in
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section 4.8.
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* The default C locale must be used during initdb because it is not
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possible to know the next-greater character in a non-C locale. You
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can create a special text_pattern_ops index for such cases that
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work only for LIKE indexing.
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possible to know the next-greatest character in a non-C locale.
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You can create a special text_pattern_ops index for such cases
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that work only for LIKE indexing.
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In pre-8.0 releases, indexes often can not be used unless the data
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types exactly match the index's column types. This is particularly
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types exactly match the index's column types. This was particularly
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true of int2, int8, and numeric column indexes.
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4.7) How do I see how the query optimizer is evaluating my query?
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@ -640,7 +642,7 @@
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WHERE lower(col) = 'abc';
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This will not use an standard index. However, if you create a
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functional index, it will be used:
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expresssion index, it will be used:
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CREATE INDEX tabindex ON tab (lower(col));
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4.9) In a query, how do I detect if a field is NULL?
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@ -649,14 +651,13 @@
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4.10) What is the difference between the various character types?
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Type Internal Name Notes
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--------------------------------------------------
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VARCHAR(n) varchar size specifies maximum length, no padding
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CHAR(n) bpchar blank padded to the specified fixed length
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TEXT text no specific upper limit on length
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BYTEA bytea variable-length byte array (null-byte safe)
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"char" char one character
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Type Internal Name Notes
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VARCHAR(n) varchar size specifies maximum length, no padding
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CHAR(n) bpchar blank padded to the specified fixed length
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TEXT text no specific upper limit on length
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BYTEA bytea variable-length byte array (null-byte safe)
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"char" char one character
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You will see the internal name when examining system catalogs and in
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some error messages.
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@ -692,9 +693,7 @@ BYTEA bytea variable-length byte array (null-byte safe)
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);
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See the create_sequence manual page for more information about
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sequences. You can also use each row's OID field as a unique value.
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However, if you need to dump and reload the database, you need to use
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pg_dump's -o option or COPY WITH OIDS option to preserve the OIDs.
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sequences.
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4.11.2) How do I get the value of a SERIAL insert?
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@ -716,16 +715,10 @@ BYTEA bytea variable-length byte array (null-byte safe)
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execute("INSERT INTO person (name) VALUES ('Blaise Pascal')");
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new_id = execute("SELECT currval('person_id_seq')");
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Finally, you could use the OID returned from the INSERT statement to
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look up the default value, though this is probably the least portable
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approach, and the oid value will wrap around when it reaches 4
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billion. In Perl, using DBI with the DBD::Pg module, the oid value is
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made available via $sth->{pg_oid_status} after $sth->execute().
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4.11.3) Doesn't currval() lead to a race condition with other users?
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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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No. currval() returns the current value assigned by your session, not
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by all sessions.
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4.11.4) Why aren't my sequence numbers reused on transaction abort? Why are
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there gaps in the numbering of my sequence/SERIAL column?
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@ -751,25 +744,7 @@ BYTEA bytea variable-length byte array (null-byte safe)
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values. TIDs change after rows are modified or reloaded. They are used
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by index entries to point to physical rows.
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4.13) What is the meaning of some of the terms used in PostgreSQL?
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Some of the source code and older documentation use terms that have
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more common usage. Here are some:
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* table, relation, class
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* row, record, tuple
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* column, field, attribute
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* retrieve, select
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* replace, update
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* append, insert
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* OID, serial value
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* portal, cursor
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* range variable, table name, table alias
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A list of general database terms can be found at:
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http://hea-www.harvard.edu/MST/simul/software/docs/pkgs/pgsql/glossary
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/glossary.html
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4.14) Why do I get the error "ERROR: Memory exhausted in AllocSetAlloc()"?
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4.13) Why do I get the error "ERROR: Memory exhausted in AllocSetAlloc()"?
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You probably have run out of virtual memory on your system, or your
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kernel has a low limit for certain resources. Try this before starting
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@ -784,11 +759,11 @@ BYTEA bytea variable-length byte array (null-byte safe)
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problem with the SQL client because the backend is returning too much
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data, try it before starting the client.
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4.15) How do I tell what PostgreSQL version I am running?
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4.14) How do I tell what PostgreSQL version I am running?
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From psql, type SELECT version();
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4.16) Why does my large-object operations get "invalid large obj
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4.15) Why does my large-object operations get "invalid large obj
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descriptor"?
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You need to put BEGIN WORK and COMMIT around any use of a large object
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@ -803,12 +778,12 @@ BYTEA bytea variable-length byte array (null-byte safe)
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If you are using a client interface like ODBC you may need to set
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auto-commit off.
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4.17) How do I create a column that will default to the current time?
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4.16) How do I create a column that will default to the current time?
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Use CURRENT_TIMESTAMP:
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CREATE TABLE test (x int, modtime timestamp DEFAULT CURRENT_TIMESTAMP );
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4.18) How do I perform an outer join?
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4.17) How do I perform an outer join?
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PostgreSQL supports outer joins using the SQL standard syntax. Here
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are two examples:
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@ -838,7 +813,7 @@ BYTEA bytea variable-length byte array (null-byte safe)
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WHERE tab1.col1 NOT IN (SELECT tab2.col1 FROM tab2)
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ORDER BY col1
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4.19) How do I perform queries using multiple databases?
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4.18) How do I perform queries using multiple databases?
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There is no way to query a database other than the current one.
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Because PostgreSQL loads database-specific system catalogs, it is
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@ -848,12 +823,12 @@ BYTEA bytea variable-length byte array (null-byte safe)
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course, a client can make simultaneous connections to different
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databases and merge the results on the client side.
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4.20) How do I return multiple rows or columns from a function?
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4.19) How do I return multiple rows or columns from a function?
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In 7.3, you can easily return multiple rows or columns from a
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function, http://techdocs.postgresql.org/guides/SetReturningFunctions.
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4.21) Why can't I reliably create/drop temporary tables in PL/PgSQL
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4.20) Why can't I reliably create/drop temporary tables in PL/PgSQL
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functions?
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PL/PgSQL caches function contents, and an unfortunate side effect is
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@ -864,7 +839,7 @@ BYTEA bytea variable-length byte array (null-byte safe)
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table access in PL/PgSQL. This will cause the query to be reparsed
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every time.
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4.22) What encryption options are available?
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4.21) What encryption options are available?
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* contrib/pgcrypto contains many encryption functions for use in SQL
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queries.
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@ -10,7 +10,7 @@
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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: Mon Jan 31 20:41:21 EST 2005</P>
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<P>Last updated: Mon Jan 31 21:31:39 EST 2005</P>
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<P>Current maintainer: Bruce Momjian (<A href=
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"mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)
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@ -101,24 +101,22 @@
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my sequence/SERIAL column?<BR>
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<A href="#4.12">4.12</A>) What is an <SMALL>OID</SMALL>? What is a
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<SMALL>TID</SMALL>?<BR>
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<A href="#4.13">4.13</A>) What is the meaning of some of the terms
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used in PostgreSQL?<BR>
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<A href="#4.14">4.14</A>) Why do I get the error <I>"ERROR: Memory
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<A href="#4.12">4.13</A>) Why do I get the error <I>"ERROR: Memory
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exhausted in AllocSetAlloc()"</I>?<BR>
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<A href="#4.15">4.15</A>) How do I tell what PostgreSQL version I
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<A href="#4.14">4.14</A>) How do I tell what PostgreSQL version I
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am running?<BR>
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<A href="#4.16">4.16</A>) Why does my large-object operations get
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<A href="#4.15">4.15</A>) Why does my large-object operations get
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<I>"invalid large obj descriptor"</I>?<BR>
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<A href="#4.17">4.17</A>) How do I create a column that will
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<A href="#4.16">4.16</A>) How do I create a column that will
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default to the current time?<BR>
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<A href="#4.18">4.18</A>) How do I perform an outer join?<BR>
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<A href="#4.19">4.19</A>) How do I perform queries using multiple
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<A href="#4.17">4.17</A>) How do I perform an outer join?<BR>
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<A href="#4.18">4.18</A>) How do I perform queries using multiple
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databases?<BR>
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<A href="#4.20">4.20</A>) How do I return multiple rows or columns
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<A href="#4.19">4.19</A>) How do I return multiple rows or columns
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from a function?<BR>
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<A href="#4.21">4.21</A>) Why can't I reliably create/drop
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<A href="#4.20">4.20</A>) Why can't I reliably create/drop
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temporary tables in PL/PgSQL functions?<BR>
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<A href="#4.22">4.22</A>) What encryption options are available?<BR>
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<A href="#4.21">4.21</A>) What encryption options are available?<BR>
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<H2 align="center">Extending PostgreSQL</H2>
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@ -531,7 +529,7 @@
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option, many <I>assert()</I>s monitor the progress of the backend
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and halt the program when something unexpected occurs.</P>
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The <I>postmaster</I> has a <I>-d</I> option that allows even more
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<P>The <I>postmaster</I> has a <I>-d</I> option that allows even more
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detailed information to be reported. The <I>-d</I> option takes a
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number that specifies the debug level. Be warned that high debug
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level values generate large log files.</P>
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@ -567,7 +565,7 @@
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<H4><A name="3.5">3.5</A>) Why do I get <I>"Sorry, too many
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clients"</I> when trying to connect?</H4>
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You have reached the default limit is 100 database sessions. You
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<P>You have reached the default limit is 100 database sessions. You
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need to increase the <I>postmaster</I>'s limit on how many
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concurrent backend processes it can start by changing the
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<I>max_connections</I> value in <I>postgresql.conf</I> and
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@ -672,19 +670,25 @@
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table, and a database?</H4>
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<P>These are the limits:</P>
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<PRE>
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Maximum size for a database? unlimited (32 TB databases exist)
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Maximum size for a table? 32 TB
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Maximum size for a row? 1.6TB
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Maximum size for a field? 1 GB
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Maximum number of rows in a table? unlimited
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Maximum number of columns in a table? 250-1600 depending on column types
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Maximum number of indexes on a table? unlimited
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</PRE>
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<CENTER>
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<TABLE BORDER=1>
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<TR><TD>Maximum size for a database?</TD><TD>unlimited (32 TB databases
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exist)</TD></TR>
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<TR><TD>Maximum size for a table?</TD><TD>32 TB</TD></TR>
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<TR><TD>Maximum size for a row?</TD><TD>1.6TB</TD></TR>
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<TR><TD>Maximum size for a field?</TD><TD>1 GB</TD></TR>
|
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<TR><TD>Maximum number of rows in a table?</TD><TD>unlimited</TD></TR>
|
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<TR><TD>Maximum number of columns in a table?</TD><TD>250-1600 depending
|
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on column types</TD></TR>
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<TR><TD>Maximum number of indexes on a
|
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table?</TD><TD>unlimited</TD></TR>
|
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</TABLE>
|
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</CENTER>
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<BR>
|
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|
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Of course, these are not actually unlimited, but limited to
|
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<P>Of course, these are not actually unlimited, but limited to
|
||||
available disk space and memory/swap space. Performance may suffer
|
||||
when these values get unusually large.
|
||||
when these values get unusually large.</P>
|
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|
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<P>The maximum table size of 32 TB does not require large file
|
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support from the operating system. Large tables are stored as
|
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@ -781,10 +785,10 @@
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<LI>The search string can not start with a character class,
|
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e.g. [a-e].</LI>
|
||||
<LI>Case-insensitive searches such as <SMALL>ILIKE</SMALL> and
|
||||
<I>~*</I> do not utilize indexes. Instead, use functional
|
||||
indexes, which are described in section <a href="#4.10">4.10</a>.</LI>
|
||||
<I>~*</I> do not utilize indexes. Instead, use expression
|
||||
indexes, which are described in section <a href="#4.8">4.8</a>.</LI>
|
||||
<LI>The default <I>C</I> locale must be used during
|
||||
<i>initdb</i> because it is not possible to know the next-greater
|
||||
<i>initdb</i> because it is not possible to know the next-greatest
|
||||
character in a non-C locale. You can create a special
|
||||
<CODE>text_pattern_ops</CODE> index for such cases that work only
|
||||
for <SMALL>LIKE</SMALL> indexing.
|
||||
@ -792,7 +796,7 @@
|
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</UL>
|
||||
|
||||
<P>In pre-8.0 releases, indexes often can not be used unless the data
|
||||
types exactly match the index's column types. This is particularly
|
||||
types exactly match the index's column types. This was particularly
|
||||
true of int2, int8, and numeric column indexes.</P>
|
||||
|
||||
<H4><A name="4.7">4.7</A>) How do I see how the query optimizer is
|
||||
@ -818,7 +822,7 @@
|
||||
</PRE>
|
||||
|
||||
This will not use an standard index. However, if you create a
|
||||
functional index, it will be used:
|
||||
expresssion index, it will be used:
|
||||
<PRE>
|
||||
CREATE INDEX tabindex ON tab (lower(col));
|
||||
</PRE>
|
||||
@ -831,16 +835,20 @@
|
||||
|
||||
<H4><A name="4.10">4.10</A>) What is the difference between the
|
||||
various character types?</H4>
|
||||
<PRE>
|
||||
Type Internal Name Notes
|
||||
--------------------------------------------------
|
||||
VARCHAR(n) varchar size specifies maximum length, no padding
|
||||
CHAR(n) bpchar blank padded to the specified fixed length
|
||||
TEXT text no specific upper limit on length
|
||||
BYTEA bytea variable-length byte array (null-byte safe)
|
||||
"char" char one character
|
||||
</PRE>
|
||||
|
||||
<CENTER>
|
||||
<TABLE BORDER=1>
|
||||
<TR><TH>Type</TH><TH>Internal Name</TH><TH>Notes</TH></TR>
|
||||
<TR><TD>VARCHAR(n)</TD><TD>varchar</TD><TD>size specifies maximum
|
||||
length, no padding</TD></TR>
|
||||
<TR><TD>CHAR(n)</TD><TD>bpchar</TD><TD>blank padded to the specified
|
||||
fixed length</TD></TR>
|
||||
<TR><TD>TEXT</TD><TD>text</TD><TD>no specific upper limit on
|
||||
length</TD></TR>
|
||||
<TR><TD>BYTEA</TD><TD>bytea</TD><TD>variable-length byte array
|
||||
(null-byte safe)</TD></TR>
|
||||
<TR><TD>"char"</TD><TD>char</TD><TD>one character</TD></TR>
|
||||
</TABLE>
|
||||
</CENTER>
|
||||
<P>You will see the internal name when examining system catalogs
|
||||
and in some error messages.</P>
|
||||
|
||||
@ -884,10 +892,7 @@ BYTEA bytea variable-length byte array (null-byte safe)
|
||||
</PRE>
|
||||
|
||||
See the <I>create_sequence</I> manual page for more information
|
||||
about sequences. You can also use each row's <I>OID</I> field as a
|
||||
unique value. However, if you need to dump and reload the database,
|
||||
you need to use <I>pg_dump</I>'s <I>-o</I> option or <SMALL>COPY
|
||||
WITH OIDS</SMALL> option to preserve the <SMALL>OID</SMALL>s.
|
||||
about sequences.
|
||||
|
||||
<H4><A name="4.11.2">4.11.2</A>) How do I get the value of a
|
||||
<SMALL>SERIAL</SMALL> insert?</H4>
|
||||
@ -918,19 +923,11 @@ BYTEA bytea variable-length byte array (null-byte safe)
|
||||
new_id = execute("SELECT currval('person_id_seq')");
|
||||
</PRE>
|
||||
|
||||
<P>Finally, you could use the <A href="#4.12"><SMALL>OID</SMALL></A>
|
||||
returned from the <SMALL>INSERT</SMALL> statement to look up the
|
||||
default value, though this is probably the least portable approach,
|
||||
and the oid value will wrap around when it reaches 4 billion.
|
||||
In Perl, using DBI with the DBD::Pg module, the oid value is made
|
||||
available via <I>$sth->{pg_oid_status}</I> after
|
||||
<I>$sth->execute()</I>.</P>
|
||||
|
||||
<H4><A name="4.11.3">4.11.3</A>) Doesn't <I>currval()</I>
|
||||
lead to a race condition with other users?</H4>
|
||||
|
||||
<P>No. <I>currval()</I> returns the current value assigned by your
|
||||
backend, not by all users.</P>
|
||||
session, not by all sessions.</P>
|
||||
|
||||
<H4><A name="4.11.4">4.11.4</A>) Why aren't my sequence numbers
|
||||
reused on transaction abort? Why are there gaps in the numbering of
|
||||
@ -964,36 +961,7 @@ BYTEA bytea variable-length byte array (null-byte safe)
|
||||
are modified or reloaded. They are used by index entries to point
|
||||
to physical rows.</P>
|
||||
|
||||
<H4><A name="4.13">4.13</A>) What is the meaning of some of the
|
||||
terms used in PostgreSQL?</H4>
|
||||
|
||||
<P>Some of the source code and older documentation use terms that
|
||||
have more common usage. Here are some:</P>
|
||||
|
||||
<UL>
|
||||
<LI>table, relation, class</LI>
|
||||
|
||||
<LI>row, record, tuple</LI>
|
||||
|
||||
<LI>column, field, attribute</LI>
|
||||
|
||||
<LI>retrieve, select</LI>
|
||||
|
||||
<LI>replace, update</LI>
|
||||
|
||||
<LI>append, insert</LI>
|
||||
|
||||
<LI><SMALL>OID</SMALL>, serial value</LI>
|
||||
|
||||
<LI>portal, cursor</LI>
|
||||
|
||||
<LI>range variable, table name, table alias</LI>
|
||||
</UL>
|
||||
|
||||
<P>A list of general database terms can be found at: <A href=
|
||||
"http://hea-www.harvard.edu/MST/simul/software/docs/pkgs/pgsql/glossary/glossary.html">http://hea-www.harvard.edu/MST/simul/software/docs/pkgs/pgsql/glossary/glossary.html</A></P>
|
||||
|
||||
<H4><A name="4.14">4.14</A>) Why do I get the error <I>"ERROR:
|
||||
<H4><A name="4.13">4.13</A>) Why do I get the error <I>"ERROR:
|
||||
Memory exhausted in AllocSetAlloc()"</I>?</H4>
|
||||
|
||||
<P>You probably have run out of virtual memory on your system,
|
||||
@ -1012,12 +980,12 @@ BYTEA bytea variable-length byte array (null-byte safe)
|
||||
backend is returning too much data, try it before starting the
|
||||
client.
|
||||
|
||||
<H4><A name="4.15">4.15</A>) How do I tell what PostgreSQL version
|
||||
<H4><A name="4.14">4.14</A>) How do I tell what PostgreSQL version
|
||||
I am running?</H4>
|
||||
|
||||
<P>From <I>psql</I>, type <CODE>SELECT version();</CODE></P>
|
||||
|
||||
<H4><A name="4.16">4.16</A>) Why does my large-object operations
|
||||
<H4><A name="4.15">4.15</A>) Why does my large-object operations
|
||||
get <I>"invalid large obj descriptor"</I>?</H4>
|
||||
|
||||
<P>You need to put <CODE>BEGIN WORK</CODE> and <CODE>COMMIT</CODE>
|
||||
@ -1033,7 +1001,7 @@ BYTEA bytea variable-length byte array (null-byte safe)
|
||||
<P>If you are using a client interface like <SMALL>ODBC</SMALL> you
|
||||
may need to set <CODE>auto-commit off.</CODE></P>
|
||||
|
||||
<H4><A name="4.17">4.17</A>) How do I create a column that will
|
||||
<H4><A name="4.16">4.16</A>) How do I create a column that will
|
||||
default to the current time?</H4>
|
||||
|
||||
<P>Use <I>CURRENT_TIMESTAMP</I>:</P>
|
||||
@ -1041,7 +1009,7 @@ BYTEA bytea variable-length byte array (null-byte safe)
|
||||
CREATE TABLE test (x int, modtime timestamp DEFAULT CURRENT_TIMESTAMP );
|
||||
</PRE>
|
||||
|
||||
<H4><A name="4.18">4.18</A>) How do I perform an outer join?</H4>
|
||||
<H4><A name="4.17">4.17</A>) How do I perform an outer join?</H4>
|
||||
|
||||
<P>PostgreSQL supports outer joins using the SQL standard syntax.
|
||||
Here are two examples:</P>
|
||||
@ -1081,7 +1049,7 @@ BYTEA bytea variable-length byte array (null-byte safe)
|
||||
ORDER BY col1
|
||||
</PRE>
|
||||
|
||||
<H4><A name="4.19">4.19</A>) How do I perform queries using
|
||||
<H4><A name="4.18">4.18</A>) How do I perform queries using
|
||||
multiple databases?</H4>
|
||||
|
||||
<P>There is no way to query a database other than the current one.
|
||||
@ -1093,7 +1061,7 @@ BYTEA bytea variable-length byte array (null-byte safe)
|
||||
connections to different databases and merge the results on the
|
||||
client side.</P>
|
||||
|
||||
<H4><A name="4.20">4.20</A>) How do I return multiple rows or
|
||||
<H4><A name="4.19">4.19</A>) How do I return multiple rows or
|
||||
columns from a function?</H4>
|
||||
|
||||
<P>In 7.3, you can easily return multiple rows or columns from a
|
||||
@ -1101,7 +1069,7 @@ BYTEA bytea variable-length byte array (null-byte safe)
|
||||
<a href="http://techdocs.postgresql.org/guides/SetReturningFunctions">
|
||||
http://techdocs.postgresql.org/guides/SetReturningFunctions</a>.
|
||||
|
||||
<H4><A name="4.21">4.21</A>) Why can't I reliably create/drop
|
||||
<H4><A name="4.20">4.20</A>) Why can't I reliably create/drop
|
||||
temporary tables in PL/PgSQL functions?</H4>
|
||||
<P>PL/PgSQL caches function contents, and an unfortunate side effect
|
||||
is that if a PL/PgSQL function accesses a temporary table, and that
|
||||
@ -1111,7 +1079,7 @@ BYTEA bytea variable-length byte array (null-byte safe)
|
||||
<SMALL>EXECUTE</SMALL> for temporary table access in PL/PgSQL. This
|
||||
will cause the query to be reparsed every time.</P>
|
||||
|
||||
<H4><A name="4.22">4.22</A>) What encryption options are available?
|
||||
<H4><A name="4.21">4.21</A>) What encryption options are available?
|
||||
</H4>
|
||||
<UL>
|
||||
<LI><I>contrib/pgcrypto</I> contains many encryption functions for
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user