SQL Tuning [Electronic resources] نسخه متنی

data

amount produced by application
2nd
3rd

denormalized

normalized

path to
[See data access; execution plans]

transferring between applications

data access

caching and

indexes and
2nd
3rd

joins and

reasons to understand

selectivity

single-table access paths

tables and
2nd
3rd
4th
5th

data type conversions, indexes enabled and disabled by
2nd

database
[See also caching; indexes; tables]

adding merged join and filter indexes to

adding missing indexes to

adding table to, for joins with hidden join filters

altering, example of

combining tables in

for exact one-to-one joins

for joins with hidden join filters

separating tables in, for one-to-one join to small subset

database blocks
[See blocks]

database vendors

SQL tuning and
2nd

tools for execution plans provided by
2nd

date-type columns in indexes

DB2

COALESCE() function

execution plans

complex

controlling

displaying
2nd
3rd

interpreting

multipart

nonrobust

robust

tables for execution-plan data

modifying queries with

nested views created on the fly

null conditions in indexed columns

optimization levels

type conversions with

updating statistics with

db2exfmt tool

DBMS_STATS package

DELETE command

deletes in index, performance effects of

denormalization

in cyclic join graph cases
2nd

when to use

denormalized data
[See also normalized data]2nd

detail join ratio
2nd
3rd

close to 1.0, affecting optimum execution plan

example of

in query diagrams

large, affecting optimum execution plan
2nd

less than 1.0

affecting optimum execution plan

caused by query diagram with multiple roots

detail table

developers, tuning their own SQL

diagrams
[See query diagrams]

directed graph
2nd
[See also query diagrams]

disconnected query diagrams

distributed filters
2nd

driving table
2nd

choosing
2nd
3rd

forcing selection of