| De-normalization of tables and explain Plan [message #9417] |
Sun, 09 November 2003 22:51  |
Reema
Messages: 50
Registered: July 2003
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Member |
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Hi All,
I would liek to know about De-Normalization i.e in what scenarios the databases are de-Normalized
Secondly, can anyboy provide me with some literature or link to same about explain plan.(The table structure of Plan_table, what r the alarming points in Expaian plan) and how should one go about analyzing explain plan.
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| Re: De-normalization of tables and explain Plan [message #9421 is a reply to message #9417] |
Mon, 10 November 2003 01:26  |
Rij
Messages: 12
Registered: September 2003
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Junior Member |
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Gimem some time for denormalisation. well u can goto tecthnet.oracle.com for literature
Plan table consists of the following columns
SQL> desc plan_table
Name Null? Type
------------------------------- -------- ----
STATEMENT_ID VARCHAR2(30)
TIMESTAMP DATE
REMARKS VARCHAR2(80)
OPERATION VARCHAR2(30)
OPTIONS VARCHAR2(30)
OBJECT_NODE VARCHAR2(128)
OBJECT_OWNER VARCHAR2(30)
OBJECT_NAME VARCHAR2(30)
OBJECT_INSTANCE NUMBER(38)
OBJECT_TYPE VARCHAR2(30)
OPTIMIZER VARCHAR2(255)
SEARCH_COLUMNS NUMBER
ID NUMBER(38)
PARENT_ID NUMBER(38)
POSITION NUMBER(38)
COST NUMBER(38)
CARDINALITY NUMBER(38)
BYTES NUMBER(38)
OTHER_TAG VARCHAR2(255)
PARTITION_START VARCHAR2(255)
PARTITION_STOP VARCHAR2(255)
PARTITION_ID NUMBER(38)
OTHER LONG
DISTRIBUTION VARCHAR2(30)
well looking at the field cost u can determine if ur query is efficient.
THe operation field tells u the type of statement u have written
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