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Markup and spell-check run over Programmer's Guide (rather incomplete still).

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This commit is contained in:
Peter Eisentraut
2001-09-10 21:58:47 +00:00
parent 51ba1c5a8c
commit a457d33516
21 changed files with 845 additions and 806 deletions
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64
doc/src/sgml/pltcl.sgml
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@@ -1,9 +1,9 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/pltcl.sgml,v 2.12 2001/08/02 15:45:55 momjian Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/pltcl.sgml,v 2.13 2001/09/10 21:58:47 petere Exp $
-->
<chapter id="pltcl">
<title>PL/Tcl - TCL Procedural Language</title>
<title>PL/Tcl - Tcl Procedural Language</title>
<indexterm zone="pltcl">
<primary>PL/Tcl</primary>
@@ -37,7 +37,7 @@ $Header: /cvsroot/pgsql/doc/src/sgml/pltcl.sgml,v 2.12 2001/08/02 15:45:55 momji
The good restriction is that everything is executed in a safe
Tcl interpreter. In addition to the limited command set of safe Tcl, only
a few commands are available to access the database via SPI and to raise
messages via elog(). There is no way to access internals of the
messages via <function>elog()</>. There is no way to access internals of the
database backend or to gain OS-level access under the permissions of the
<productname>Postgres</productname> user ID, as a C function can do.
Thus, any unprivileged database user may be
@@ -157,7 +157,7 @@ CREATE FUNCTION overpaid_2 (EMP) RETURNS bool AS '
</para>
<para>
To help protect PL/Tcl procedures from unwanted side effects,
an array is made available to each procedure via the upvar
an array is made available to each procedure via the <function>upvar</>
command. The global name of this variable is the procedure's internal
name and the local name is GD. It is recommended that GD be used
for private status data of a procedure. Use regular Tcl global variables
@@ -210,7 +210,7 @@ CREATE FUNCTION overpaid_2 (EMP) RETURNS bool AS '
<listitem>
<para>
A Tcl list of the tables field names prefixed with an empty list element.
So looking up an element name in the list with the lsearch Tcl command
So looking up an element name in the list with the <function>lsearch</> Tcl command
returns the same positive number starting from 1 as the fields are numbered
in the pg_attribute system catalog.
</para>
@@ -344,7 +344,7 @@ CREATE TRIGGER trig_mytab_modcount BEFORE INSERT OR UPDATE ON mytab
<indexterm>
<primary>elog</primary>
</indexterm>
<term>elog <replaceable>level</replaceable> <replaceable>msg</replaceable></term>
<term><function>elog</> <replaceable>level</replaceable> <replaceable>msg</replaceable></term>
<listitem>
<para>
Fire a log message. Possible levels are NOTICE, ERROR,
@@ -355,7 +355,7 @@ CREATE TRIGGER trig_mytab_modcount BEFORE INSERT OR UPDATE ON mytab
</varlistentry>
<varlistentry>
<term>quote <replaceable>string</replaceable></term>
<term><function>quote</> <replaceable>string</replaceable></term>
<listitem>
<para>
Duplicates all occurrences of single quote and backslash characters.
@@ -398,7 +398,7 @@ CREATE TRIGGER trig_mytab_modcount BEFORE INSERT OR UPDATE ON mytab
<indexterm>
<primary>spi_lastoid</primary>
</indexterm>
<term>spi_lastoid</term>
<term><function>spi_lastoid</></term>
<listitem>
<para>
Returns the OID of the last query if it was an INSERT.
@@ -407,7 +407,7 @@ CREATE TRIGGER trig_mytab_modcount BEFORE INSERT OR UPDATE ON mytab
</varlistentry>
<varlistentry>
<term>spi_exec ?-count <replaceable>n</replaceable>? ?-array <replaceable>name</replaceable>? <replaceable>query</replaceable> ?<replaceable>loop-body</replaceable>?</term>
<term><function>spi_exec</function> <literal>?-count <replaceable>n</replaceable>? ?-array <replaceable>name</replaceable>? <replaceable>query</replaceable> ?<replaceable>loop-body</replaceable>?</literal></term>
<listitem>
<para>
Call parser/planner/optimizer/executor for query.
@@ -446,45 +446,45 @@ spi_exec -array C "SELECT * FROM pg_class" {
</varlistentry>
<varlistentry>
<term>spi_prepare <replaceable>query</replaceable> <replaceable>typelist</replaceable></term>
<term><function>spi_prepare</function> <replaceable>query</replaceable> <replaceable>typelist</replaceable></term>
<listitem>
<para>
Prepares AND SAVES a query plan for later execution. It is a bit different
from the C level SPI_prepare in that the plan is automatically copied to the
toplevel memory context. Thus, there is currently no way of preparing a
top-level memory context. Thus, there is currently no way of preparing a
plan without saving it.
</para>
<para>
If the query references arguments, the type names must be given as a Tcl
list. The return value from spi_prepare is a query ID to be used in
subsequent calls to spi_execp. See spi_execp for a sample.
list. The return value from <function>spi_prepare</function> is a query ID to be used in
subsequent calls to <function>spi_execp</function>. See <function>spi_execp</function> for a sample.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>spi_exec ?-count <replaceable>n</replaceable>? ?-array<replaceable>name</replaceable>? ?-nulls<replaceable>string</replaceable>? <replaceable>queryid</replaceable> ?<replaceable>value-list</replaceable>? ?<replaceable>loop-body</replaceable>?</term>
<term><function>spi_exec</> <literal>?-count <replaceable>n</replaceable>? ?-array<replaceable>name</replaceable>? ?-nulls<replaceable>string</replaceable>? <replaceable>queryid</replaceable> ?<replaceable>value-list</replaceable>? ?<replaceable>loop-body</replaceable>?</literal></term>
<listitem>
<para>
Execute a prepared plan from spi_prepare with variable substitution.
The optional -count value tells spi_execp the maximum number of rows
Execute a prepared plan from <function>spi_prepare</> with variable substitution.
The optional <literal>-count</literal> value tells <function>spi_execp</> the maximum number of rows
to be processed by the query.
</para>
<para>
The optional value for -nulls is a string of spaces and 'n' characters
telling spi_execp which of the values are NULL's. If given, it must
The optional value for <literal>-nulls</> is a string of spaces and 'n' characters
telling <function>spi_execp</function> which of the values are NULL's. If given, it must
have exactly the length of the number of values.
</para>
<para>
The queryid is the ID returned by the spi_prepare call.
The <parameter>queryid</> is the ID returned by the <function>spi_prepare</function> call.
</para>
<para>
If there was a typelist given to spi_prepare, a Tcl list of values of
If there was a <parameter>typelist</> given to <function>spi_prepare</function>, a Tcl list of values of
exactly the same length must be given to spi_execp after the query. If
the type list on spi_prepare was empty, this argument must be omitted.
</para>
<para>
If the query is a SELECT statement, the same as described for spi_exec
If the query is a SELECT statement, the same as described for <function>spi_exec</>
happens for the loop-body and the variables for the fields selected.
</para>
<para>
@@ -506,7 +506,7 @@ CREATE FUNCTION t1_count(int4, int4) RETURNS int4 AS '
Note that each backslash that Tcl should see must be doubled in
the query creating the function, since the main parser processes
backslashes too on CREATE FUNCTION.
Inside the query string given to spi_prepare should
Inside the query string given to <function>spi_prepare</> should
really be dollar signs to mark the parameter positions and to not let
$1 be substituted by the value given in the first function call.
</para>
@@ -515,18 +515,20 @@ CREATE FUNCTION t1_count(int4, int4) RETURNS int4 AS '
<varlistentry>
<term>
Modules and the unknown command
Modules and the <function>unknown</> command
</term>
<listitem>
<para>
PL/Tcl has a special support for things often used. It recognizes two
magic tables, pltcl_modules and pltcl_modfuncs.
If these exist, the module 'unknown' is loaded into the interpreter
right after creation. Whenever an unknown Tcl procedure is called,
the unknown proc is asked to check if the procedure is defined in one
of the modules. If this is true, the module is loaded on demand.
To enable this behavior, the PL/Tcl call handler must be compiled
with -DPLTCL_UNKNOWN_SUPPORT set.
PL/Tcl has a special support for things often used. It
recognizes two magic tables, <literal>pltcl_modules</> and
<literal>pltcl_modfuncs</>. If these exist, the module
'unknown' is loaded into the interpreter right after
creation. Whenever an unknown Tcl procedure is called, the
unknown proc is asked to check if the procedure is defined in
one of the modules. If this is true, the module is loaded on
demand. To enable this behavior, the
<productname>PostgreSQL</> must be configured with the option
<option>--enable-pltcl-unknown</option>.
</para>
<para>
There are support scripts to maintain these tables in the modules