From da9db5693001989a724cdaf122a4eda9de137ee7 Mon Sep 17 00:00:00 2001 From: Bruce Momjian Date: Thu, 9 Jul 1998 17:59:49 +0000 Subject: [PATCH] change to . --- src/tools/backend/index.html | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/src/tools/backend/index.html b/src/tools/backend/index.html index f068e671e4..6aff709af6 100644 --- a/src/tools/backend/index.html +++ b/src/tools/backend/index.html @@ -25,13 +25,13 @@ HREF="../../include/nodes/parsenodes.h">SelectStmt. The query is then identified as a Utility query or a more complex query. A Utility query is processed by a query-specific function in commands. A complex query, like -SELECT, UPDATE, and -DELETE requires much more handling. +SELECT, UPDATE, and +DELETE requires much more handling.

The parser takes a complex query, and creates a Query structure that contains all the elements used by complex queries. Query.qual holds the -WHERE clause qualification, which is filled in by +WHERE clause qualification, which is filled in by transformWhereClause(). Each table referenced in the query is represented by a RangeTableEntry, and they @@ -39,19 +39,19 @@ are linked together to form the range table of the query, which is generated by makeRangeTable(). Query.rtable holds the query's range table.

-Certain queries, like SELECT, return columns of data. Other -queries, like INSERT and UPDATE, specify the columns +Certain queries, like SELECT, return columns of data. Other +queries, like INSERT and UPDATE, specify the columns modified by the query. These column references are converted to Resdom entries, which are linked together to make up the target list of the query. The target list is stored in Query.targetList, which is generated by transformTargetList().

-Other query elements, like aggregates(SUM()), GROUP BY, -and ORDER BY are also stored in their own Query fields. +Other query elements, like aggregates(SUM()), GROUP BY, +and ORDER BY are also stored in their own Query fields.

-The next step is for the Query to be modified by any VIEWS or -RULES that may apply to the query. This is performed by the VIEWS or +RULES that may apply to the query. This is performed by the rewrite system.

The optimizer takes the Query @@ -60,7 +60,7 @@ HREF="../..//include/nodes/plannodes.h">Plan, which contains the operations to be performed to execute the query. The path module determines the best table join order and join type of each table in the RangeTable, using -Query.qual(WHERE clause) to consider optimal index usage. +Query.qual(WHERE clause) to consider optimal index usage.

The Plan is then passed to the executor for execution, and the result -- GitLab