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Commit50b5d4b

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Add mention of function CREATE INDEX usage.
1 parent0c9790e commit50b5d4b

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-39
lines changed

2 files changed

+41
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‎doc/src/sgml/ref/create_index.sgml‎

Lines changed: 32 additions & 30 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
<!--
2-
$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_index.sgml,v 1.27 2002/03/22 19:20:38 petere Exp $
2+
$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_index.sgml,v 1.28 2002/04/11 23:20:04 momjian Exp $
33
PostgreSQL documentation
44
-->
55

@@ -76,9 +76,10 @@ CREATE [ UNIQUE ] INDEX <replaceable class="parameter">index_name</replaceable>
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<term><replaceable class="parameter">acc_method</replaceable></term>
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<listitem>
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<para>
79-
The name of the access method to be used for
80-
the index. The default access method is <literal>BTREE</literal>.
81-
<application>PostgreSQL</application> provides four access methods for indexes:
79+
The name of the access method to be used for the index. The
80+
default access method is <literal>BTREE</literal>.
81+
<application>PostgreSQL</application> provides four access
82+
methods for indexes:
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<variablelist>
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<varlistentry>
@@ -225,26 +226,27 @@ ERROR: Cannot create index: 'index_name' already exists.
225226
</para>
226227

227228
<para>
228-
In the second syntax shown above, an index is defined
229-
on the result of a user-specified function
230-
<replaceable class="parameter">func_name</replaceable> applied
231-
to one or more columns of a single table.
232-
These <firstterm>functional indexes</firstterm>
233-
can be used to obtain fast access to data
234-
based on operators that would normally require some
235-
transformation to apply them to the base data.
229+
In the second syntax shown above, an index is defined on the result
230+
of a user-specified function <replaceable
231+
class="parameter">func_name</replaceable> applied to one or more
232+
columns of a single table. These <firstterm>functional
233+
indexes</firstterm> can be used to obtain fast access to data based
234+
on operators that would normally require some transformation to apply
235+
them to the base data. For example, a functional index on
236+
<literal>upper(col)</> would allow the clause
237+
<literal>WHERE upper(col) = 'JIM'</> to use an index.
236238
</para>
237239

238240
<para>
239-
<application>PostgreSQL</application> provides B-tree, R-tree, hash, and GiST access methods for
240-
indexes.The B-tree access method is an implementation of
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Lehman-Yao high-concurrency B-trees.The R-tree access method
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implements standard R-trees using Guttman's quadratic split algorithm.
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The hash access method is an implementation of Litwin's linear
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hashing.We mention the algorithms used solely to indicate that all
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of these access methods are fully dynamic and do not have to be
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optimized periodically (as is the case with, for example, static hash
247-
access methods).
241+
<application>PostgreSQL</application> provides B-tree, R-tree, hash,
242+
and GiST access methods forindexes. The B-tree access method is an
243+
implementation ofLehman-Yao high-concurrency B-trees. The R-tree
244+
access methodimplements standard R-trees using Guttman's quadratic
245+
split algorithm.The hash access method is an implementation of
246+
Litwin's linearhashing. We mention the algorithms used solely to
247+
indicate that allof these access methods are fully dynamic and do
248+
not have to beoptimized periodically (as is the case with, for
249+
example, static hashaccess methods).
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</para>
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<para>
@@ -338,18 +340,18 @@ ERROR: Cannot create index: 'index_name' already exists.
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339341
<para>
340342
An <firstterm>operator class</firstterm> can be specified for each
341-
column of an index.The operator class identifies the operators to
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beused by the index for that column. For example, a B-tree index on
343+
column of an index. The operator class identifies the operators to be
344+
used by the index for that column. For example, a B-tree index on
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four-byte integers would use the <literal>int4_ops</literal> class;
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this operator class includes comparison functions for four-byte
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integers.In practice the default operator class for the field's
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datatype is usually sufficient. The main point of having operator classes
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integers. In practice the default operator class for the field's data
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type is usually sufficient. The main point of having operator classes
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is that for some data types, there could be more than one meaningful
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ordering.For example, we might want to sort a complex-number data type
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either by absolute value or by real part.We could do this by defining
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two operator classes for the data type and then selecting the proper
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class when making an index.There are also some operator classes with
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special purposes:
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ordering. For example, we might want to sort a complex-number data
351+
typeeither by absolute value or by real part. We could do this by
352+
definingtwo operator classes for the data type and then selecting
353+
the properclass when making an index. There are also some operator
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classes withspecial purposes:
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<itemizedlist>
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<listitem>

‎src/backend/commands/command.c‎

Lines changed: 9 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.172 2002/04/02 08:51:50 inoue Exp $
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* $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.173 2002/04/11 23:20:04 momjian Exp $
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*
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* NOTES
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* The PerformAddAttribute() code, like most of the relation
@@ -604,10 +604,10 @@ AlterTableAlterColumnDropNotNull(Oid myrelid,
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elog(ERROR,"ALTER TABLE: Cannot alter system attribute \"%s\"",
605605
colName);
606606

607-
/*
607+
/*
608608
* Check that the attribute is not in a primary key
609609
*/
610-
610+
611611
/* Loop over all indices on the relation */
612612
indexoidlist=RelationGetIndexList(rel);
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@@ -986,9 +986,9 @@ AlterTableAlterColumnFlags(Oid myrelid,
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elog(ERROR,"ALTER TABLE: relation \"%s\" is not a table",
987987
RelationGetRelationName(rel));
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/*
989+
/*
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* we allow statistics case for system tables
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*/
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*/
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if (*flagType!='S'&&
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!allowSystemTableMods
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&&IsSystemRelationName(RelationGetRelationName(rel)))
@@ -1911,7 +1911,7 @@ LockTableCommand(LockStmt *lockstmt)
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/*
19121912
* CREATE SCHEMA
19131913
*/
1914-
void
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void
19151915
CreateSchemaCommand(CreateSchemaStmt*stmt)
19161916
{
19171917
constchar*schemaName=stmt->schemaname;
@@ -1976,13 +1976,13 @@ CreateSchemaCommand(CreateSchemaStmt *stmt)
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Node*parsetree= (Node*)lfirst(parsetree_item);
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List*querytree_list,
19781978
*querytree_item;
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1979+
19801980
querytree_list=parse_analyze(parsetree,NULL);
1981-
1981+
19821982
foreach(querytree_item,querytree_list)
19831983
{
19841984
Query*querytree= (Query*)lfirst(querytree_item);
1985-
1985+
19861986
/* schemas should contain only utility stmts */
19871987
Assert(querytree->commandType==CMD_UTILITY);
19881988
/* do this step */

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