oracle sql tuning books

, Microseconds_per_second ms_per_sec, pct_of_time pct from Opsg_delta_report where Microseconds_per_second > 0; Monitoring the usage of indexes: With In_plan_objects as(SELECT DISTINCT object_name from V$sql_plan WHERE object_owner = ' SCOTT ')SELECT table_name,Index_name,CaseWhen object_name was NULL then' NO 'ELSE' YES 'END as In_cached_planFrom User_indexesLeft OUTER JOIN in_plan_objectsOn (index_name = object_name);4. Identify the SQL st

Label:1. Pure hand-crafted Tools: Programmer's hands Features: Handwritten client and server-side validation code 2. Semi-manual semi-automatic Tools: Jquery.validate (client) + dataannotations dataannotationsextensions (server side) Features: Client handwritten partial validation code, server side only need to declare validation rules 3. Fully Automatic Tools: Jquery.validate jquery.validate.unobtrusive (client) + dataannotations dataannotationsextensions (server side) Features: Only server-

Tags: merging RDBMS LTE data file nbsp Select line div2016-11-22Subquery: Scalar subquery inline view (In-line views) semi-join/reverse-connect scalar subquery Select followed by subquery similar to a custom function to overwrite an inline view (In-line view) from followed by a subquery similar to Design view sub-query A condom query is a garbage design that can cause performance problems. A semi-connection is a subquery that has a in/exists in the back of where it is followed by a subquery with

rownumObviously, this writing will result in reading the table first, then sorting, and then taking the first 5 records, the plan is as follows:If we write like this, the semantics are the same, but it saves a lot of reading and sorting costs:Select/*+ Index (T1,IDX1_T1) */* from T1 where rownumThe execution plan for this SQL is as follows:As you can see, the SQL does not follow the hint instructions and s

SQL Server database self-optimizing release time under large data volume:2013-12-17 15:19:00 Source: Forum anonymous Keywords: database development1.1: Add secondary data filesStarting with SQL SERVER 2005, the database does not generate the NDF data file by default, generally there is a master data file (MDF) is enough, but some large databases, because of a lot of information, and query frequently, so in

of the SQL statement, and combine its resource consumption and related statistics, trace files to analyze its execution plan is reasonable;2, through the correction measures (such as adjusting the SQL execution plan, etc.) to adjust the SQL to shorten its execution time, here is the guiding principle of tuning is the

read times. The ways to refine each statement are:Check Optimizer statistics，Check the interpretation plan for the most efficient access pathMeasuringtry to replace SQL constructs, and test for possible new indexes, manifested views, and partitions. Test the performance of the entire application using the optimized SQL statement. Is overall performance improved? The method is reliable, but somewhat dilator

that does not read data or execute plans, however, Oracle has provided a large number of built-in SQL optimization tools since 10 Gb. For example: ADDM, SQL Access Advisor, SQL Tuning Advisor, Automatic SQL

in a plan baseline. If Plan_name is also specified, the corresponding execution plan is displayed.Note: In order to preserve backward compatibility, the statement will be compiled with this storage outline if the stored outline pair of an SQL statement for a user session is active. In addition, even if automatic scheduled capture is enabled for the session, the optimizer is not stored in SMB with a plan that is generated by the storage outline.Althou

This document is compiled and summarized based on relevant information. It mainly describes the most authoritative and correct methods and steps for obtaining SQL statement execution plans in Oracle databases. This document is compiled and summarized based on relevant information. It mainly describes the most authoritative and correct methods and steps for obtaining SQL