Use of explain Plan

Hi
I am using explain plan for query.How can i optimize query to see result of explain plan.
Thanx

Collect statistics, use hints, create indexes... many ways. You try using of outlines, but it is not common practice. Usually you haven't to influence the plan directly

Similar Messages

  • Question regarding using of Explain Plan

    Hi. I'm new with Oracle Queries so I have a little obstacles about understanding. I want to learn how to use Explain Plan feature from Oracle
    I am using Oracle 9i as back end .
    Please tell me how can i use feature of Explain Plan Feature for the below query.
    SELECT * FROM emp WHERE empno = 7369
    Thanks in advance.

    [email protected] wrote:
    Hi. I'm new with Oracle Queries so I have a little obstacles about understanding. I want to learn how to use Explain Plan feature from Oracle
    I am using Oracle 9i as back end .
    Please tell me how can i use feature of Explain Plan Feature for the below query.
    SELECT * FROM emp WHERE empno = 7369
    Kiran,
    Firstly , before anything else, I would suggest to change your handle to anything else and remove the email id from it. Its not good to have the id displayed in any public forum.
    About the question, unfortunately, its not that easy to answer. To understand explain plan and how to use it, you need to understand that algorithm/mechanism, whatever you feel like saying, that generates it. Because, explain plan is just the outcome of that mechanism, a final product, its the result of some inputs given by you in the form of your query, predicates, joins and their types and that all bring up the explain plan. Explain plan is basically the constitution of some steps which are used /fixed by optimizer to run the query. I would suggest that you read this page from cover to cover to understand some of the steps and their meanings which are shown to you in the plan. I am giving 10g link as this is a more better version of optimizer than the previous ones and I would suggest you to do experiments on 10g only.
    http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/optimops.htm#i21299
    And I would suggest that you collect these following books and start reading them. I haven't yet found any thing better than these books.
    [Cost Based Oracle Fundamentals (Jonathan Lewis)|http://www.amazon.com/Cost-Based-Oracle-Fundamentals-Experts-Voice/dp/1590596366]
    [Troubleshooting Oracle Performance(Christian Antognini )|http://www.amazon.com/Troubleshooting-Oracle-Performance-Christian-Antognini/dp/1590599179/ref=sr_1_1?ie=UTF8&s=books&qid=1240078634&sr=1-1]
    [Effectuve Oracle By Design(Tom Kyte)|http://www.amazon.com/Effective-Oracle-Design-Osborne-ORACLE/dp/0072230657/ref=sr_1_1?ie=UTF8&s=books&qid=1240078698&sr=1-1]
    It would be real long journey before the mazes of optimizer and explain would be clear so make sure you have patience as well.
    HTH
    Aman....

  • Why bother to use explain plan?

    All my colleagues used the third party applications, Crystal Report or TAOD, to query data from the 10g R2 database for some kind of reporting. The problem is they always created the query with multiple outer join (> 10 tables) and they WRITE the codes without using the explain plan. They simply used the query for result of the moment and the query they wrote only were used for few time (< 3), because the manager requested the report kept changing the requirement. They did it on both Dev and Prod
    I think it is bad practice, how can I convience them to change their practice?

    The concept that something is ad hoc and therefore doesn't matter can break down pretty quickly when a bright light is shined upon it. But what you are fighting here is more a question of politics than technology.
    If the system is still chugging along at an acceptable speed, no end-user complaints, and practices in your organization range from sloppy to lazy you should probably just polish up your resume and move to a job where people care about professional standards and doing a good job.
    To change a practice such as this usually one must get to the level of childish schoolyard play and create a competitive atmosphere. Take one of those slow queries and tune it. Challenge someone to do better than you did. Offer a beer to anyone that can write it more efficiently than you did, etc. Make it a game.
    But don't be surprised if the reason they aren't running explain plan is that:
    1. They don't know how
    2. They know how but don't know how to read the output
    3. They know how to read the output but haven't a clue what to do about it.
    As an example ... I know a lot of people that think they know how to output an explain plan. In truth not 10% of them understand this:
    SELECT * FROM TABLE(dbms_xplan.display_cursor('cpm9ss48qd32f', 0));
    http://www.psoug.org/reference/dbms_xplan.html
    Which is really rather sad.

  • "Explain Plan" in Oracle SQL Developer is greyed out

    Hi all,
    I know this is not the right place to post this, but I have look around and do not know where to post question about Oracle SQL Developer - I presume this tool is also discussed here in this forum.
    My question is very simple (I presume):
    1. I installed Oracle SQL Developer 3.0.04.
    2. I added a new DB connection to a DB hosted in one of my servers in the LAN.
    3. However, when I am writing some SQL queries, I intend to use the "Explain Plan" feature, but it is being greyed out (disabled).
    4. How can I enable it back?

    Hello,
    {forum:id=260}
    Regards
    Marcus

  • Explain plan: "Select statement"

    Hi,
    I'm using the explain plan command to retrieve information about query execution. In particular I want to estimate query execution time.
    Let's consider the following example:
    "| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |"
    "| 0 | SELECT STATEMENT | | 4775 | 484K| 98886 (1)| 00:19:47 |"
    "| 1 | HASH GROUP BY | | 4775 | 484K| 98886 (1)| 00:19:47 |"
    "|* 2 | MAT_VIEW ACCESS FULL| Materialized_view1 | 4775 | 484K| 98884 (1)| 00:19:47 |"
    In the calculation of total execution time should i consider the "select statement" operation?
    The total execution time can be calculated like this: Time(Select statement) + Time(hash group by) + Time(access full)=19.47*3=58.41. Is it right?
    Thanks

    No, the expected time is 00:19:47. No time is expected to be spent in steps 0 and 1.

  • Explain plan changing for the same sql

    Hi All,
    In a E Business suite application, we have the 10.2.0.4 Database.
    One of the program is running a select stmt which is using different explain plan one in a month which is causing issue in the program running for longer time.
    Ex : When it uses the index A, it is running fine. When it uses the index B, it is running for longer time.
    Can you please advice on the possible reasons for the same sql to choose index B instead of index A some times.
    Thanks,
    Rakesh

    It could be that the SQL is question got aged out of the shared pool and when it came to be reparsed - the values in the bind variables were such that access via index b was more attractive than access via index a.
    Could you please send the query and the good and bad plans and all other information that might help diagnose the problem..
    Note: we had a similiar case where plans suddenly changed for no apperant reason (on 10.2.0.2) - we found that under certain circumstances the optimizer would not peek into the bind varaibles to derive the execution path.

  • Explain Plan is disabled - why?

    Hi
    I was using SqlDeveloper 1.0 and had no problems using the Explain Plan feature. Now I upgraded to 1.1 (did not migrate settings) and now the explain plan button is always greyed out. Am I missing something to enable the explain plan feature?
    Thanks

    Are all the buttons grayed out on the worksheet or just the explain plan button? If you look at your worksheet, is the drop list on the right hand side populated? i.e does it display your user connection? If not, select your connection in the drop kist and the icons will change from gray to available.
    You say in your message that you upgraded to 1.1. I assume you did a fresh install in a new directory.
    Regards
    Sue

  • Explain plan - lower cost but higher response time in 11g compared to 10g

    Hello,
    I have a strange scenario where 'm migrating a db from standalone Sun FS running 10g RDBMS to a 2-Node Sun/ASM 11g RAC env. The issue is with response time of queries -
    In 11g Env:
    SQL> select last_analyzed, num_rows from dba_tables where owner='MARKETHEALTH' and table_name='NCP_DETAIL_TAB';
    LAST_ANALYZED NUM_ROWS
    11-08-2012 18:21:12 3413956
    Elapsed: 00:00:00.30
    In 10g Env:
    SQL> select last_analyzed, num_rows from dba_tables where owner='MARKETHEALTH' and table_name='NCP_DETAIL_TAB';
    LAST_ANAL NUM_ROWS
    07-NOV-12 3502160
    Elapsed: 00:00:00.04If you look @ the response times, even a simple query on the dba_tables takes ~8 times. Any ideas what might be causing this? I have compared the XPlans and they are exactly the same, moreover, the cost is less in the 11g env compared to the 10g env, but still the response time is higher.
    BTW - 'm running the queries directly on the server, so no network latency in play here.
    Thanks in advance
    aBBy.

    *11g Env:*
    PLAN_TABLE_OUTPUT
    Plan hash value: 4147636274
    | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
    | 0 | SELECT STATEMENT | | 1104 | 376K| 394 (1)| 00:00:05 |
    | 1 | SORT ORDER BY | | 1104 | 376K| 394 (1)| 00:00:05 |
    | 2 | TABLE ACCESS BY INDEX ROWID| NCP_DETAIL_TAB | 1104 | 376K| 393 (1)| 00:00:05 |
    |* 3 | INDEX RANGE SCAN | IDX_NCP_DET_TAB_US | 1136 | | 15 (0)| 00:00:01 |
    PLAN_TABLE_OUTPUT
    Predicate Information (identified by operation id):
    3 - access("UNIT_ID"='ten03.burien.wa.seattle.comcast.net')
    15 rows selected.
    *10g Env:*
    SQL> select * from table(dbms_xplan.display);
    PLAN_TABLE_OUTPUT
    Plan hash value: 4147636274
    | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
    | 0 | SELECT STATEMENT | | 1137 | 373K| 389 (1)| 00:00:05 |
    | 1 | SORT ORDER BY | | 1137 | 373K| 389 (1)| 00:00:05 |
    | 2 | TABLE ACCESS BY INDEX ROWID| NCP_DETAIL_TAB | 1137 | 373K| 388 (1)| 00:00:05 |
    |* 3 | INDEX RANGE SCAN | IDX_NCP_DET_TAB_US | 1137 | | 15 (0)| 00:00:01 |
    Predicate Information (identified by operation id):
    3 - access("UNIT_ID"='ten03.burien.wa.seattle.comcast.net')
    15 rows selected.
    The query used is:
    explain plan for
    select
    NCP_DETAIL_ID ,
    NCP_ID ,
    STATUS_ID ,
    FIBER_NODE ,
    NODE_DESC ,
    GL ,
    FTA_ID ,
    OLD_BUS_ID ,
    VIRTUAL_NODE_IND ,
    SERVICE_DELIVERY_TYPE ,
    HHP_AUDIT_QTY ,
    COMMUNITY_SERVED ,
    CMTS_CARD_ID ,
    OPTICAL_TRANSMITTER ,
    OPTICAL_RECEIVER ,
    LASER_GROUP_ID ,
    UNIT_ID ,
    DS_SLOT ,
    DOWNSTREAM_PORT_ID ,
    DS_PORT_OR_MOD_RF_CHAN ,
    DOWNSTREAM_FREQ ,
    DOWNSTREAM_MODULATION ,
    UPSTREAM_PORT_ID ,
    UPSTREAM_PORT ,
    UPSTREAM_FREQ ,
    UPSTREAM_MODULATION ,
    UPSTREAM_WIDTH ,
    UPSTREAM_LOGICAL_PORT ,
    UPSTREAM_PHYSICAL_PORT ,
    NCP_DETAIL_COMMENTS ,
    ROW_CHANGE_IND ,
    STATUS_DATE ,
    STATUS_USER ,
    MODEM_COUNT ,
    NODE_ID ,
    NODE_FIELD_ID ,
    CREATE_USER ,
    CREATE_DT ,
    LAST_CHANGE_USER ,
    LAST_CHANGE_DT ,
    UNIT_ID_IP ,
    US_SLOT ,
    MOD_RF_CHAN_ID ,
    DOWNSTREAM_LOGICAL_PORT ,
    STATE
    from markethealth.NCP_DETAIL_TAB
    WHERE UNIT_ID = :B1
    ORDER BY UNIT_ID, DS_SLOT, DS_PORT_OR_MOD_RF_CHAN, FIBER_NODE
    This is the query used for Query 1.
    Stats differences are:
    1. Rownum differes by apprx - 90K more rows in 10g env
    2. RAC env has 4 additional columns (excluded in the select statement for analysis purposes).
    3. Gather Stats was performed with estimate_percent = 20 in 10g and estimate_percent = 50 in 11g.

  • Explain plan privileges

    Hi,
    in order to use the explain plan feature inside the worksheet (sqldev 2.1, 15 Dec 09), sqldev requires the SELECT_CATALOG_ROLE and the SELECT ANY DICTIONARY privileges.
    Why?
    1. Even with only the classic CONNECT and RESOURCE roles granted, I can execute "explain plan for ..." and "select * from table(dbms_xplan.display);" and get the xplan.
    2. Don't you see the problems in persuading those hard core DBAs, that developers need xplan - and yes, they can read them???

    1. seems one of those bugs... there are more areas that need such privileges. DEV?
    2. was requested at the Exchange, but sadly rejected. You can request it again, but seen the scarce support on votes, it would just be rejected again.
    Regards,
    K.

  • Query tunning in Oracle using Explain Plan

    Adding to my below question: I have now modified the query and the path shownby 'Explain plan' has reduced. The 'Time' column of plan_table is also showing much lesser value. However, some people are suggesting me to consider the time required by the query to execute on Toad. Will it be practical? Please help!!
    Hi, I am using Oracle 11g. I need to optimize a Select query(Need to minimize the execution time). I need to know how 'Explain Plan' would help me. I know how to use Explain Plan command. I refer Plan_table table to see the details of the plan. Please guide me regarding which columns of the Plan_table should be considered while modifying the query for optimization. Some people say, 'Time' column should be considered, some say 'Bytes' etc. Some suggest on minimizing the full table scans, while some people say that I should minimize the total no. operations (less no. of rows should be displayed in Plan_table). As per an experienced friend of mine, full table scans should be reduced (for e.g. if there are 5 full table scans in the plan, then try to reduce them to less than 5. ). However, if I consider any full table scan operation in the plan_table, its shows value of 'time' column as only 1 which is very very less. Does this mean the full scan is actually taking very less time?? If yes, then this means full table scans are very fast in my case and no need to work on them. Some articles suggest that plan shown by 'Explain Plan' command is not necessarily followed while executing the query. So what should I look for then? How should I optimize the query and how will I come to know that it's optimized?? Please help!!...
    Edited by: 885901 on Sep 20, 2011 2:10 AM

    885901 wrote:
    Hi, I am using Oracle 11g. I need to optimize a Select query(Need to minimize the execution time). I need to know how 'Explain Plan' would help me. I know how to use Explain Plan command. I refer Plan_table table to see the details of the plan. Please guide me regarding which columns of the Plan_table should be considered while modifying the query for optimization. Some people say, 'Time' column should be considered, some say 'Bytes' etc. Some suggest on minimizing the full table scans, while some people say that I should minimize the total no. operations (less no. of rows should be displayed in Plan_table). As per an experienced friend of mine, full table scans should be reduced (for e.g. if there are 5 full table scans in the plan, then try to reduce them to less than 5. ). However, if I consider any full table scan operation in the plan_table, its shows value of 'time' column as only 1 which is very very less. Does this mean the full scan is actually taking very less time?? If yes, then this means full table scans are very fast in my case and no need to work on them. Some articles suggest that plan shown by 'Explain Plan' command is not necessarily followed while executing the query. So what should I look for then? How should I optimize the query and how will I come to know that it's optimized?? Please help!!...how fast is fast enough?

  • Explain plan result for a long-running query used in data-warehousing. Tuni

    I have executed an explain plan for a query that is used in a data-warehousing application.
    This sql is taking too long to execute as it is visiting 24 partitions.
    Where each partition contains data for 1 month month, so it fetches last 2 year data.
    And each partition has a million or so rows.
    All this is kept in table prescrip_retail. So this table has 24 partitions.
    abc@def>explain plan set statement_id='dwh_query'
    2 for
    3 SELECT r.pier_account_id,
    4 p.presc_num,
    5 spm.product_id,
    6 p.month,
    7 t.best_call_state,
    8 sum(p.trx_count)
    9 FROM rlup_assigned_account r,
    10 temp_presc_num_TEST t,
    11 retail.prescrip_retail p,
    12 sherlock.sherlock_product_mapping spm
    13 WHERE spm.product_id like '056%'
    14 and t.CLIENT_ID='934759'
    15 and p.month >= add_months(sysdate,-24)
    16 and spm.mds6 = p.product_id
    17 and t.CLIENT_ID = p.presc_num
    18 and r.ndc_pyr_id = p.payer_plan
    19 and t.best_call_state = r.ST
    20 GROUP BY r.pier_account_id,
    21 p.presc_num,
    22 spm.product_id,
    23 p.month,
    24 t.best_call_state;
    Explained.
    abc@def>ed
    Wrote file afiedt.buf
    1 select operation,options,optimizer,cost,cardinality,partition_start,partition_stop
    2 from plan_table
    3* where statement_id='dwh_query'
    abc@def>/
    OPERATION OPTIONS OPTIMIZER COST CARDINALITY
    PARTITION_START
    PARTITION_STOP
    SELECT STATEMENT CHOOSE 850 1
    SORT GROUP BY 850 1
    NESTED LOOPS 848 1
    HASH JOIN 845 3
    HASH JOIN 842 6
    TABLE ACCESS FULL ANALYZED 1 6
    PARTITION RANGE ITERATOR
    KEY
    36
    TABLE ACCESS BY LOCAL INDEX ROWID ANALYZED 839 166
    KEY
    36
    BITMAP CONVERSION TO ROWIDS
    BITMAP INDEX SINGLE VALUE
    KEY
    36
    TABLE ACCESS FULL 2 50
    TABLE ACCESS BY INDEX ROWID ANALYZED 1 149501
    INDEX UNIQUE SCAN ANALYZED 149501
    13 rows selected.

    Here is the create statement for PRESCRIP_RETAIL table:
    I have observed 2 things:
    1. In the query the following joins are present.
    13 WHERE spm.product_id like '056%'
    14 and t.CLIENT_ID='934759'
    15 and p.month >= add_months(sysdate,-24)
    16 and spm.mds6 = p.product_id
    17 and t.CLIENT_ID = p.presc_num
    18 and r.ndc_pyr_id = p.payer_plan
    19 and t.best_call_state = r.ST
    Index exist for p.product_id,p.presc_num,p.payer_plan as you can see below.
    However, the index does not exist for month.
    I am also doing search for month.
    I feel if I create a "partitioned index" on month, query performance should improve.
    Q Can you provide me the syntax for creating a partitioned index on month?
    2.The following tables are used in the query:
    9 FROM rlup_assigned_account r,
    10 temp_presc_num_TEST t,
    11 retail.prescrip_retail p,
    12 sherlock.sherlock_product_mapping spm
    In these tables, apart from sherlock.sherlock_product_mapping table the statistics that exist is old.
    I need to analyse on table level as well as column level.
    For example:
    Table prescrip_retail is analyzed in 2002,
    table temp_presc_num_TEST is not analysed at all.
    table rlup_assigned_account is analysed in Feb 2007.
    sherlock_product_mapping is the only table that has updated statistics, analysed on Oct. 2007
    Here is the table creation statement of PRESCRIP_RETAIL and index on it.
    Prompt Table PRESCRIP_RETAIL;
    -- PRESCRIP_RETAIL (Table)
    -- Row count:2806673860
    CREATE TABLE RETAIL.PRESCRIP_RETAIL
    PRESC_NUM NUMBER,
    PIER_NUM CHAR(8),
    RELID CHAR(9) NOT NULL,
    ME_NUM CHAR(10) NOT NULL,
    PRODUCT_ID CHAR(6) NOT NULL,
    PRODUCT_FRMSTR CHAR(1) NOT NULL,
    PAYER_PLAN CHAR(6) NOT NULL,
    MONTH DATE NOT NULL,
    PYMT_CODE CHAR(1) NOT NULL,
    NRX_COUNT NUMBER(7) NOT NULL,
    NRX_QUANTITY NUMBER(9) NOT NULL,
    NRX_DOLLARS NUMBER(13,2) NOT NULL,
    TRX_COUNT NUMBER(7) NOT NULL,
    TRX_QUANTITY NUMBER(9) NOT NULL,
    TRX_DOLLARS NUMBER(13,2) NOT NULL
    TABLESPACE PRESC_PARTITION_29
    NOLOGGING
    PARTITION BY RANGE (MONTH)
    PARTITION PRESC200406 VALUES LESS THAN (TO_DATE(' 2004-07-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_30,
    PARTITION PRESC200407 VALUES LESS THAN (TO_DATE(' 2004-08-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_31,
    PARTITION PRESC200408 VALUES LESS THAN (TO_DATE(' 2004-09-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_32,
    PARTITION PRESC200409 VALUES LESS THAN (TO_DATE(' 2004-10-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_33,
    PARTITION PRESC200410 VALUES LESS THAN (TO_DATE(' 2004-11-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_34,
    PARTITION PRESC200411 VALUES LESS THAN (TO_DATE(' 2004-12-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_35,
    PARTITION PRESC200412 VALUES LESS THAN (TO_DATE(' 2005-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_36,
    PARTITION PRESC200501 VALUES LESS THAN (TO_DATE(' 2005-02-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_01,
    PARTITION PRESC200502 VALUES LESS THAN (TO_DATE(' 2005-03-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_02,
    PARTITION PRESC200503 VALUES LESS THAN (TO_DATE(' 2005-04-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_03,
    PARTITION PRESC200504 VALUES LESS THAN (TO_DATE(' 2005-05-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_04,
    PARTITION PRESC200505 VALUES LESS THAN (TO_DATE(' 2005-06-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_05,
    PARTITION PRESC200506 VALUES LESS THAN (TO_DATE(' 2005-07-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_06,
    PARTITION PRESC200507 VALUES LESS THAN (TO_DATE(' 2005-08-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_07,
    PARTITION PRESC200508 VALUES LESS THAN (TO_DATE(' 2005-09-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_08,
    PARTITION PRESC200509 VALUES LESS THAN (TO_DATE(' 2005-10-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_09,
    PARTITION PRESC200510 VALUES LESS THAN (TO_DATE(' 2005-11-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_10,
    PARTITION PRESC200511 VALUES LESS THAN (TO_DATE(' 2005-12-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_11,
    PARTITION PRESC200512 VALUES LESS THAN (TO_DATE(' 2006-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_12,
    PARTITION PRESC200601 VALUES LESS THAN (TO_DATE(' 2006-02-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_13,
    PARTITION PRESC200602 VALUES LESS THAN (TO_DATE(' 2006-03-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_14,
    PARTITION PRESC200603 VALUES LESS THAN (TO_DATE(' 2006-04-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_15,
    PARTITION PRESC200604 VALUES LESS THAN (TO_DATE(' 2006-05-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_16,
    PARTITION PRESC200605 VALUES LESS THAN (TO_DATE(' 2006-06-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_17,
    PARTITION PRESC200606 VALUES LESS THAN (TO_DATE(' 2006-07-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_18,
    PARTITION PRESC200607 VALUES LESS THAN (TO_DATE(' 2006-08-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_19,
    PARTITION PRESC200608 VALUES LESS THAN (TO_DATE(' 2006-09-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_20,
    PARTITION PRESC200609 VALUES LESS THAN (TO_DATE(' 2006-10-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_21,
    PARTITION PRESC200610 VALUES LESS THAN (TO_DATE(' 2006-11-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_22,
    PARTITION PRESC200611 VALUES LESS THAN (TO_DATE(' 2006-12-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_23,
    PARTITION PRESC200612 VALUES LESS THAN (TO_DATE(' 2007-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_24,
    PARTITION PRESC200701 VALUES LESS THAN (TO_DATE(' 2007-02-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_25,
    PARTITION PRESC200702 VALUES LESS THAN (TO_DATE(' 2007-03-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_26,
    PARTITION PRESC200703 VALUES LESS THAN (TO_DATE(' 2007-04-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_27,
    PARTITION PRESC200704 VALUES LESS THAN (TO_DATE(' 2007-05-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_28,
    PARTITION PRESC200705 VALUES LESS THAN (TO_DATE(' 2007-06-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
    LOGGING
    TABLESPACE PRESC_PARTITION_29
    NOCACHE
    NOPARALLEL;
    Prompt Index BX2_PRESC_PAYER;
    -- BX2_PRESC_PAYER (Index)
    -- Dependencies:
    -- PRESCRIP_RETAIL (Table)
    CREATE BITMAP INDEX RETAIL.BX2_PRESC_PAYER ON RETAIL.PRESCRIP_RETAIL
    (PAYER_PLAN)
    TABLESPACE PRESC_PARTITION_29
    LOGGING
    LOCAL (
    PARTITION PRESC200406
    NOLOGGING
    TABLESPACE PRESC_PARTITION_30,
    PARTITION PRESC200407
    NOLOGGING
    TABLESPACE PRESC_PARTITION_31,
    PARTITION PRESC200408
    NOLOGGING
    TABLESPACE PRESC_PARTITION_32,
    PARTITION PRESC200409
    NOLOGGING
    TABLESPACE PRESC_PARTITION_33,
    PARTITION PRESC200410
    NOLOGGING
    TABLESPACE PRESC_PARTITION_34,
    PARTITION PRESC200411
    NOLOGGING
    TABLESPACE PRESC_PARTITION_35,
    PARTITION PRESC200412
    NOLOGGING
    TABLESPACE PRESC_PARTITION_36,
    PARTITION PRESC200501
    NOLOGGING
    TABLESPACE PRESC_PARTITION_01,
    PARTITION PRESC200502
    NOLOGGING
    TABLESPACE PRESC_PARTITION_02,
    PARTITION PRESC200503
    NOLOGGING
    TABLESPACE PRESC_PARTITION_03,
    PARTITION PRESC200504
    NOLOGGING
    TABLESPACE PRESC_PARTITION_04,
    PARTITION PRESC200505
    NOLOGGING
    TABLESPACE PRESC_PARTITION_05,
    PARTITION PRESC200506
    NOLOGGING
    TABLESPACE PRESC_PARTITION_06,
    PARTITION PRESC200507
    NOLOGGING
    TABLESPACE PRESC_PARTITION_07,
    PARTITION PRESC200508
    NOLOGGING
    TABLESPACE PRESC_PARTITION_08,
    PARTITION PRESC200509
    NOLOGGING
    TABLESPACE PRESC_PARTITION_09,
    PARTITION PRESC200510
    NOLOGGING
    TABLESPACE PRESC_PARTITION_10,
    PARTITION PRESC200511
    NOLOGGING
    TABLESPACE PRESC_PARTITION_11,
    PARTITION PRESC200512
    NOLOGGING
    TABLESPACE PRESC_PARTITION_12,
    PARTITION PRESC200601
    NOLOGGING
    TABLESPACE PRESC_PARTITION_13,
    PARTITION PRESC200602
    NOLOGGING
    TABLESPACE PRESC_PARTITION_14,
    PARTITION PRESC200603
    NOLOGGING
    TABLESPACE PRESC_PARTITION_15,
    PARTITION PRESC200604
    NOLOGGING
    TABLESPACE PRESC_PARTITION_16,
    PARTITION PRESC200605
    NOLOGGING
    TABLESPACE PRESC_PARTITION_17,
    PARTITION PRESC200606
    NOLOGGING
    TABLESPACE PRESC_PARTITION_18,
    PARTITION PRESC200607
    NOLOGGING
    TABLESPACE PRESC_PARTITION_19,
    PARTITION PRESC200608
    NOLOGGING
    TABLESPACE PRESC_PARTITION_20,
    PARTITION PRESC200609
    NOLOGGING
    TABLESPACE PRESC_PARTITION_21,
    PARTITION PRESC200610
    NOLOGGING
    TABLESPACE PRESC_PARTITION_22,
    PARTITION PRESC200611
    NOLOGGING
    TABLESPACE PRESC_PARTITION_23,
    PARTITION PRESC200612
    NOLOGGING
    TABLESPACE PRESC_PARTITION_24,
    PARTITION PRESC200701
    NOLOGGING
    TABLESPACE PRESC_PARTITION_25,
    PARTITION PRESC200702
    NOLOGGING
    TABLESPACE PRESC_PARTITION_26,
    PARTITION PRESC200703
    NOLOGGING
    TABLESPACE PRESC_PARTITION_27,
    PARTITION PRESC200704
    NOLOGGING
    TABLESPACE PRESC_PARTITION_28,
    PARTITION PRESC200705
    NOLOGGING
    TABLESPACE PRESC_PARTITION_29
    NOPARALLEL;
    Prompt Index BX3_PRESC_PAYERCD;
    -- BX3_PRESC_PAYERCD (Index)
    -- Dependencies:
    -- PRESCRIP_RETAIL (Table)
    CREATE BITMAP INDEX RETAIL.BX3_PRESC_PAYERCD ON RETAIL.PRESCRIP_RETAIL
    (PYMT_CODE)
    TABLESPACE PRESC_PARTITION_29
    NOLOGGING
    LOCAL (
    PARTITION PRESC200406
    NOLOGGING
    TABLESPACE PRESC_PARTITION_30,
    PARTITION PRESC200407
    NOLOGGING
    TABLESPACE PRESC_PARTITION_31,
    PARTITION PRESC200408
    NOLOGGING
    TABLESPACE PRESC_PARTITION_32,
    PARTITION PRESC200409
    NOLOGGING
    TABLESPACE PRESC_PARTITION_33,
    PARTITION PRESC200410
    NOLOGGING
    TABLESPACE PRESC_PARTITION_34,
    PARTITION PRESC200411
    NOLOGGING
    TABLESPACE PRESC_PARTITION_35,
    PARTITION PRESC200412
    NOLOGGING
    TABLESPACE PRESC_PARTITION_36,
    PARTITION PRESC200501
    NOLOGGING
    TABLESPACE PRESC_PARTITION_01,
    PARTITION PRESC200502
    NOLOGGING
    TABLESPACE PRESC_PARTITION_02,
    PARTITION PRESC200503
    NOLOGGING
    TABLESPACE PRESC_PARTITION_03,
    PARTITION PRESC200504
    NOLOGGING
    TABLESPACE PRESC_PARTITION_04,
    PARTITION PRESC200505
    NOLOGGING
    TABLESPACE PRESC_PARTITION_05,
    PARTITION PRESC200506
    NOLOGGING
    TABLESPACE PRESC_PARTITION_06,
    PARTITION PRESC200507
    NOLOGGING
    TABLESPACE PRESC_PARTITION_07,
    PARTITION PRESC200508
    NOLOGGING
    TABLESPACE PRESC_PARTITION_08,
    PARTITION PRESC200509
    NOLOGGING
    TABLESPACE PRESC_PARTITION_09,
    PARTITION PRESC200510
    NOLOGGING
    TABLESPACE PRESC_PARTITION_10,
    PARTITION PRESC200511
    NOLOGGING
    TABLESPACE PRESC_PARTITION_11,
    PARTITION PRESC200512
    NOLOGGING
    TABLESPACE PRESC_PARTITION_12,
    PARTITION PRESC200601
    NOLOGGING
    TABLESPACE PRESC_PARTITION_13,
    PARTITION PRESC200602
    NOLOGGING
    TABLESPACE PRESC_PARTITION_14,
    PARTITION PRESC200603
    NOLOGGING
    TABLESPACE PRESC_PARTITION_15,
    PARTITION PRESC200604
    NOLOGGING
    TABLESPACE PRESC_PARTITION_16,
    PARTITION PRESC200605
    NOLOGGING
    TABLESPACE PRESC_PARTITION_17,
    PARTITION PRESC200606
    NOLOGGING
    TABLESPACE PRESC_PARTITION_18,
    PARTITION PRESC200607
    NOLOGGING
    TABLESPACE PRESC_PARTITION_19,
    PARTITION PRESC200608
    NOLOGGING
    TABLESPACE PRESC_PARTITION_20,
    PARTITION PRESC200609
    NOLOGGING
    TABLESPACE PRESC_PARTITION_21,
    PARTITION PRESC200610
    NOLOGGING
    TABLESPACE PRESC_PARTITION_22,
    PARTITION PRESC200611
    NOLOGGING
    TABLESPACE PRESC_PARTITION_23,
    PARTITION PRESC200612
    NOLOGGING
    TABLESPACE PRESC_PARTITION_24,
    PARTITION PRESC200701
    NOLOGGING
    TABLESPACE PRESC_PARTITION_25,
    PARTITION PRESC200702
    NOLOGGING
    TABLESPACE PRESC_PARTITION_26,
    PARTITION PRESC200703
    NOLOGGING
    TABLESPACE PRESC_PARTITION_27,
    PARTITION PRESC200704
    NOLOGGING
    TABLESPACE PRESC_PARTITION_28,
    PARTITION PRESC200705
    NOLOGGING
    TABLESPACE PRESC_PARTITION_29
    NOPARALLEL;
    Prompt Index BX4_PRESC_PRESC;
    -- BX4_PRESC_PRESC (Index)
    -- Dependencies:
    -- PRESCRIP_RETAIL (Table)
    CREATE BITMAP INDEX RETAIL.BX4_PRESC_PRESC ON RETAIL.PRESCRIP_RETAIL
    (PRESC_NUM)
    TABLESPACE PRESC_PARTITION_29
    NOLOGGING
    LOCAL (
    PARTITION PRESC200406
    NOLOGGING
    TABLESPACE PRESC_PARTITION_30,
    PARTITION PRESC200407
    NOLOGGING
    TABLESPACE PRESC_PARTITION_31,
    PARTITION PRESC200408
    NOLOGGING
    TABLESPACE PRESC_PARTITION_32,
    PARTITION PRESC200409
    NOLOGGING
    TABLESPACE PRESC_PARTITION_33,
    PARTITION PRESC200410
    NOLOGGING
    TABLESPACE PRESC_PARTITION_34,
    PARTITION PRESC200411
    NOLOGGING
    TABLESPACE PRESC_PARTITION_35,
    PARTITION PRESC200412
    NOLOGGING
    TABLESPACE PRESC_PARTITION_36,
    PARTITION PRESC200501
    NOLOGGING
    TABLESPACE PRESC_PARTITION_01,
    PARTITION PRESC200502
    NOLOGGING
    TABLESPACE PRESC_PARTITION_02,
    PARTITION PRESC200503
    NOLOGGING
    TABLESPACE PRESC_PARTITION_03,
    PARTITION PRESC200504
    NOLOGGING
    TABLESPACE PRESC_PARTITION_04,
    PARTITION PRESC200505
    NOLOGGING
    TABLESPACE PRESC_PARTITION_05,
    PARTITION PRESC200506
    NOLOGGING
    TABLESPACE PRESC_PARTITION_06,
    PARTITION PRESC200507
    NOLOGGING
    TABLESPACE PRESC_PARTITION_07,
    PARTITION PRESC200508
    NOLOGGING
    TABLESPACE PRESC_PARTITION_08,
    PARTITION PRESC200509
    NOLOGGING
    TABLESPACE PRESC_PARTITION_09,
    PARTITION PRESC200510
    NOLOGGING
    TABLESPACE PRESC_PARTITION_10,
    PARTITION PRESC200511
    NOLOGGING
    TABLESPACE PRESC_PARTITION_11,
    PARTITION PRESC200512
    NOLOGGING
    TABLESPACE PRESC_PARTITION_12,
    PARTITION PRESC200601
    NOLOGGING
    TABLESPACE PRESC_PARTITION_13,
    PARTITION PRESC200602
    NOLOGGING
    TABLESPACE PRESC_PARTITION_14,
    PARTITION PRESC200603
    NOLOGGING
    TABLESPACE PRESC_PARTITION_15,
    PARTITION PRESC200604
    NOLOGGING
    TABLESPACE PRESC_PARTITION_16,
    PARTITION PRESC200605
    NOLOGGING
    TABLESPACE PRESC_PARTITION_17,
    PARTITION PRESC200606
    NOLOGGING
    TABLESPACE PRESC_PARTITION_18,
    PARTITION PRESC200607
    NOLOGGING
    TABLESPACE PRESC_PARTITION_19,
    PARTITION PRESC200608
    NOLOGGING
    TABLESPACE PRESC_PARTITION_20,
    PARTITION PRESC200609
    NOLOGGING
    TABLESPACE PRESC_PARTITION_21,
    PARTITION PRESC200610
    NOLOGGING
    TABLESPACE PRESC_PARTITION_22,
    PARTITION PRESC200611
    NOLOGGING
    TABLESPACE PRESC_PARTITION_23,
    PARTITION PRESC200612
    NOLOGGING
    TABLESPACE PRESC_PARTITION_24,
    PARTITION PRESC200701
    NOLOGGING
    TABLESPACE PRESC_PARTITION_25,
    PARTITION PRESC200702
    NOLOGGING
    TABLESPACE PRESC_PARTITION_26,
    PARTITION PRESC200703
    NOLOGGING
    TABLESPACE PRESC_PARTITION_27,
    PARTITION PRESC200704
    NOLOGGING
    TABLESPACE PRESC_PARTITION_28,
    PARTITION PRESC200705
    NOLOGGING
    TABLESPACE PRESC_PARTITION_29
    NOPARALLEL;
    Prompt Index BX5_PRESC_PIER;
    -- BX5_PRESC_PIER (Index)
    -- Dependencies:
    -- PRESCRIP_RETAIL (Table)
    CREATE BITMAP INDEX RETAIL.BX5_PRESC_PIER ON RETAIL.PRESCRIP_RETAIL
    (PIZR_NUM)
    TABLESPACE PRESC_PARTITION_29
    LOGGING
    LOCAL (
    PARTITION PRESC200406
    NOLOGGING
    TABLESPACE PRESC_PARTITION_30,
    PARTITION PRESC200407
    NOLOGGING
    TABLESPACE PRESC_PARTITION_31,
    PARTITION PRESC200408
    NOLOGGING
    TABLESPACE PRESC_PARTITION_32,
    PARTITION PRESC200409
    NOLOGGING
    TABLESPACE PRESC_PARTITION_33,
    PARTITION PRESC200410
    NOLOGGING
    TABLESPACE PRESC_PARTITION_34,
    PARTITION PRESC200411
    NOLOGGING
    TABLESPACE PRESC_PARTITION_35,
    PARTITION PRESC200412
    NOLOGGING
    TABLESPACE PRESC_PARTITION_36,
    PARTITION PRESC200501
    NOLOGGING
    TABLESPACE PRESC_PARTITION_01,
    PARTITION PRESC200502
    NOLOGGING
    TABLESPACE PRESC_PARTITION_02,
    PARTITION PRESC200503
    NOLOGGING
    TABLESPACE PRESC_PARTITION_03,
    PARTITION PRESC200504
    NOLOGGING
    TABLESPACE PRESC_PARTITION_04,
    PARTITION PRESC200505
    NOLOGGING
    TABLESPACE PRESC_PARTITION_05,
    PARTITION PRESC200506
    NOLOGGING
    TABLESPACE PRESC_PARTITION_06,
    PARTITION PRESC200507
    NOLOGGING
    TABLESPACE PRESC_PARTITION_07,
    PARTITION PRESC200508
    NOLOGGING
    TABLESPACE PRESC_PARTITION_08,
    PARTITION PRESC200509
    NOLOGGING
    TABLESPACE PRESC_PARTITION_09,
    PARTITION PRESC200510
    NOLOGGING
    TABLESPACE PRESC_PARTITION_10,
    PARTITION PRESC200511
    NOLOGGING
    TABLESPACE PRESC_PARTITION_11,
    PARTITION PRESC200512
    NOLOGGING
    TABLESPACE PRESC_PARTITION_12,
    PARTITION PRESC200601
    NOLOGGING
    TABLESPACE PRESC_PARTITION_13,
    PARTITION PRESC200602
    NOLOGGING
    TABLESPACE PRESC_PARTITION_14,
    PARTITION PRESC200603
    NOLOGGING
    TABLESPACE PRESC_PARTITION_15,
    PARTITION PRESC200604
    NOLOGGING
    TABLESPACE PRESC_PARTITION_16,
    PARTITION PRESC200605
    NOLOGGING
    TABLESPACE PRESC_PARTITION_17,
    PARTITION PRESC200606
    NOLOGGING
    TABLESPACE PRESC_PARTITION_18,
    PARTITION PRESC200607
    NOLOGGING
    TABLESPACE PRESC_PARTITION_19,
    PARTITION PRESC200608
    NOLOGGING
    TABLESPACE PRESC_PARTITION_20,
    PARTITION PRESC200609
    NOLOGGING
    TABLESPACE PRESC_PARTITION_21,
    PARTITION PRESC200610
    NOLOGGING
    TABLESPACE PRESC_PARTITION_22,
    PARTITION PRESC200611
    NOLOGGING
    TABLESPACE PRESC_PARTITION_23,
    PARTITION PRESC200612
    NOLOGGING
    TABLESPACE PRESC_PARTITION_24,
    PARTITION PRESC200701
    NOLOGGING
    TABLESPACE PRESC_PARTITION_25,
    PARTITION PRESC200702
    NOLOGGING
    TABLESPACE PRESC_PARTITION_26,
    PARTITION PRESC200703
    NOLOGGING
    TABLESPACE PRESC_PARTITION_27,
    PARTITION PRESC200704
    NOLOGGING
    TABLESPACE PRESC_PARTITION_28,
    PARTITION PRESC200705
    NOLOGGING
    TABLESPACE PRESC_PARTITION_29
    NOPARALLEL;
    Prompt Index BX6_PRESC_RELID;
    -- BX6_PRESC_RELID (Index)
    -- Dependencies:
    -- PRESCRIP_RETAIL (Table)
    CREATE BITMAP INDEX RETAIL.BX6_PRESC_RELID ON RETAIL.PRESCRIP_RETAIL
    (RELID)
    TABLESPACE PRESC_PARTITION_29
    LOGGING
    LOCAL (
    PARTITION PRESC200406
    NOLOGGING
    TABLESPACE PRESC_PARTITION_30,
    PARTITION PRESC200407
    NOLOGGING
    TABLESPACE PRESC_PARTITION_31,
    PARTITION PRESC200408
    NOLOGGING
    TABLESPACE PRESC_PARTITION_32,
    PARTITION PRESC200409
    NOLOGGING
    TABLESPACE PRESC_PARTITION_33,
    PARTITION PRESC200410
    NOLOGGING
    TABLESPACE PRESC_PARTITION_34,
    PARTITION PRESC200411
    NOLOGGING
    TABLESPACE PRESC_PARTITION_35,
    PARTITION PRESC200412
    NOLOGGING
    TABLESPACE PRESC_PARTITION_36,
    PARTITION PRESC200501
    NOLOGGING
    TABLESPACE PRESC_PARTITION_01,
    PARTITION PRESC200502
    NOLOGGING
    TABLESPACE PRESC_PARTITION_02,
    PARTITION PRESC200503
    NOLOGGING
    TABLESPACE PRESC_PARTITION_03,
    PARTITION PRESC200504
    NOLOGGING
    TABLESPACE PRESC_PARTITION_04,
    PARTITION PRESC200505
    NOLOGGING
    TABLESPACE PRESC_PARTITION_05,
    PARTITION PRESC200506
    NOLOGGING
    TABLESPACE PRESC_PARTITION_06,
    PARTITION PRESC200507
    NOLOGGING
    TABLESPACE PRESC_PARTITION_07,
    PARTITION PRESC200508
    NOLOGGING
    TABLESPACE PRESC_PARTITION_08,
    PARTITION PRESC200509
    NOLOGGING
    TABLESPACE PRESC_PARTITION_09,
    PARTITION PRESC200510
    NOLOGGING
    TABLESPACE PRESC_PARTITION_10,
    PARTITION PRESC200511
    NOLOGGING
    TABLESPACE PRESC_PARTITION_11,
    PARTITION PRESC200512
    NOLOGGING
    TABLESPACE PRESC_PARTITION_12,
    PARTITION PRESC200601
    NOLOGGING
    TABLESPACE PRESC_PARTITION_13,
    PARTITION PRESC200602
    NOLOGGING
    TABLESPACE PRESC_PARTITION_14,
    PARTITION PRESC200603
    NOLOGGING
    TABLESPACE PRESC_PARTITION_15,
    PARTITION PRESC200604
    NOLOGGING
    TABLESPACE PRESC_PARTITION_16,
    PARTITION PRESC200605
    NOLOGGING
    TABLESPACE PRESC_PARTITION_17,
    PARTITION PRESC200606
    NOLOGGING
    TABLESPACE PRESC_PARTITION_18,
    PARTITION PRESC200607
    NOLOGGING
    TABLESPACE PRESC_PARTITION_19,
    PARTITION PRESC200608
    NOLOGGING
    TABLESPACE PRESC_PARTITION_20,
    PARTITION PRESC200609
    NOLOGGING
    TABLESPACE PRESC_PARTITION_21,
    PARTITION PRESC200610
    NOLOGGING
    TABLESPACE PRESC_PARTITION_22,
    PARTITION PRESC200611
    NOLOGGING
    TABLESPACE PRESC_PARTITION_23,
    PARTITION PRESC200612
    NOLOGGING
    TABLESPACE PRESC_PARTITION_24,
    PARTITION PRESC200701
    NOLOGGING
    TABLESPACE PRESC_PARTITION_25,
    PARTITION PRESC200702
    NOLOGGING
    TABLESPACE PRESC_PARTITION_26,
    PARTITION PRESC200703
    NOLOGGING
    TABLESPACE PRESC_PARTITION_27,
    PARTITION PRESC200704
    NOLOGGING
    TABLESPACE PRESC_PARTITION_28,
    PARTITION PRESC200705
    NOLOGGING
    TABLESPACE PRESC_PARTITION_29
    NOPARALLEL;
    Prompt Index BX7_PRESC_ME;
    -- BX7_PRESC_ME (Index)
    -- Dependencies:
    -- PRESCRIP_RETAIL (Table)
    CREATE BITMAP INDEX RETAIL.BX7_PRESC_ME ON RETAIL.PRESCRIP_RETAIL
    (ME_NUM)
    TABLESPACE PRESC_PARTITION_29
    LOGGING
    LOCAL (
    PARTITION PRESC200406
    NOLOGGING
    TABLESPACE PRESC_PARTITION_30,
    PARTITION PRESC200407
    NOLOGGING
    TABLESPACE PRESC_PARTITION_31,
    PARTITION PRESC200408
    NOLOGGING
    TABLESPACE PRESC_PARTITION_32,
    PARTITION PRESC200409
    NOLOGGING
    TABLESPACE PRESC_PARTITION_33,
    PARTITION PRESC200410
    NOLOGGING
    TABLESPACE PRESC_PARTITION_34,
    PARTITION PRESC200411
    NOLOGGING
    TABLESPACE PRESC_PARTITION_35,
    PARTITION PRESC200412
    NOLOGGING
    TABLESPACE PRESC_PARTITION_36,
    PARTITION PRESC200501
    NOLOGGING
    TABLESPACE PRESC_PARTITION_01,
    PARTITION PRESC200502
    NOLOGGING
    TABLESPACE PRESC_PARTITION_02,
    PARTITION PRESC200503
    NOLOGGING
    TABLESPACE PRESC_PARTITION_03,
    PARTITION PRESC200504
    NOLOGGING
    TABLESPACE PRESC_PARTITION_04,
    PARTITION PRESC200505
    NOLOGGING
    TABLESPACE PRESC_PARTITION_05,
    PARTITION PRESC200506
    NOLOGGING
    TABLESPACE PRESC_PARTITION_06,
    PARTITION PRESC200507
    NOLOGGING
    TABLESPACE PRESC_PARTITION_07,
    PARTITION PRESC200508
    NOLOGGING
    TABLESPACE PRESC_PARTITION_08,
    PARTITION PRESC200509
    NOLOGGING
    TABLESPACE PRESC_PARTITION_09,
    PARTITION PRESC200510
    NOLOGGING
    TABLESPACE PRESC_PARTITION_10,
    PARTITION PRESC200511
    NOLOGGING
    TABLESPACE PRESC_PARTITION_11,
    PARTITION PRESC200512
    NOLOGGING
    TABLESPACE PRESC_PARTITION_12,
    PARTITION PRESC200601
    NOLOGGING
    TABLESPACE PRESC_PARTITION_13,
    PARTITION PRESC200602
    NOLOGGING
    TABLESPACE PRESC_PARTITION_14,
    PARTITION PRESC200603
    NOLOGGING
    TABLESPACE PRESC_PARTITION_15,
    PARTITION PRESC200604
    NOLOGGING
    TABLESPACE PRESC_PARTITION_16,
    PARTITION PRESC200605
    NOLOGGING
    TABLESPACE PRESC_PARTITION_17,
    PARTITION PRESC200606
    NOLOGGING
    TABLESPACE PRESC_PARTITION_18,
    PARTITION PRESC200607
    NOLOGGING
    TABLESPACE PRESC_PARTITION_19,
    PARTITION PRESC200608
    NOLOGGING
    TABLESPACE PRESC_PARTITION_20,
    PARTITION PRESC200609
    NOLOGGING
    TABLESPACE PRESC_PARTITION_21,
    PARTITION PRESC200610
    NOLOGGING
    TABLESPACE PRESC_PARTITION_22,
    PARTITION PRESC200611
    NOLOGGING
    TABLESPACE PRESC_PARTITION_23,
    PARTITION PRESC200612
    NOLOGGING
    TABLESPACE PRESC_PARTITION_24,
    PARTITION PRESC200701
    NOLOGGING
    TABLESPACE PRESC_PARTITION_25,
    PARTITION PRESC200702
    NOLOGGING
    TABLESPACE PRESC_PARTITION_26,
    PARTITION PRESC200703
    NOLOGGING
    TABLESPACE PRESC_PARTITION_27,
    PARTITION PRESC200704
    NOLOGGING
    TABLESPACE PRESC_PARTITION_28,
    PARTITION PRESC200705
    NOLOGGING
    TABLESPACE PRESC_PARTITION_29
    NOPARALLEL;
    Prompt Index BX1_PRESC_PROD;
    -- BX1_PRESC_PROD (Index)
    -- Dependencies:
    -- PRESCRIP_RETAIL (Table)
    CREATE BITMAP INDEX RETAIL.BX1_PRESC_PROD ON RETAIL.PRESCRIP_RETAIL
    (PRODUCT_ID, PRODUCT_FRMSTR)
    TABLESPACE PRESC_PARTITION_29
    LOGGING
    LOCAL (
    PARTITION PRESC200406
    NOLOGGING
    TABLESPACE PRESC_PARTITION_30,
    PARTITION PRESC200407
    NOLOGGING
    TABLESPACE PRESC_PARTITION_31,
    PARTITION PRESC200408
    NOLOGGING
    TABLESPACE PRESC_PARTITION_32,
    PARTITION PRESC200409
    NOLOGGING
    TABLESPACE PRESC_PARTITION_33,
    PARTITION PRESC200410
    NOLOGGING
    TABLESPACE PRESC_PARTITION_34,
    PARTITION PRESC200411
    NOLOGGING
    TABLESPACE PRESC_PARTITION_35,
    PARTITION PRESC200412
    NOLOGGING
    TABLESPACE PRESC_PARTITION_36,
    PARTITION PRESC200501
    NOLOGGING
    TABLESPACE PRESC_PARTITION_01,
    PARTITION PRESC200502
    NOLOGGING
    TABLESPACE PRESC_PARTITION_02,
    PARTITION PRESC200503
    NOLOGGING
    TABLESPACE PRESC_PARTITION_03,
    PARTITION PRESC200504
    NOLOGGING
    TABLESPACE PRESC_PARTITION_04,
    PARTITION PRESC200505
    NOLOGGING
    TABLESPACE PRESC_PARTITION_05,
    PARTITION PRESC200506
    NOLOGGING
    TABLESPACE PRESC_PARTITION_06,
    PARTITION PRESC200507
    NOLOGGING
    TABLESPACE PRESC_PARTITION_07,
    PARTITION PRESC200508
    NOLOGGING
    TABLESPACE PRESC_PARTITION_08,
    PARTITION PRESC200509
    NOLOGGING
    TABLESPACE PRESC_PARTITION_09,
    PARTITION PRESC200510
    NOLOGGING
    TABLESPACE PRESC_PARTITION_10,
    PARTITION PRESC200511
    NOLOGGING
    TABLESPACE PRESC_PARTITION_11,
    PARTITION PRESC200512
    NOLOGGING
    TABLESPACE PRESC_PARTITION_12,
    PARTITION PRESC200601
    NOLOGGING
    TABLESPACE PRESC_PARTITION_13,
    PARTITION PRESC200602
    NOLOGGING
    TABLESPACE PRESC_PARTITION_14,
    PARTITION PRESC200603
    NOLOGGING
    TABLESPACE PRESC_PARTITION_15,
    PARTITION PRESC200604
    NOLOGGING
    TABLESPACE PRESC_PARTITION_16,
    PARTITION PRESC200605
    NOLOGGING
    TABLESPACE PRESC_PARTITION_17,
    PARTITION PRESC200606
    NOLOGGING
    TABLESPACE PRESC_PARTITION_18,
    PARTITION PRESC200607
    NOLOGGING
    TABLESPACE PRESC_PARTITION_19,
    PARTITION PRESC200608
    NOLOGGING
    TABLESPACE PRESC_PARTITION_20,
    PARTITION PRESC200609
    NOLOGGING
    TABLESPACE PRESC_PARTITION_21,
    PARTITION PRESC200610
    NOLOGGING
    TABLESPACE PRESC_PARTITION_22,
    PARTITION PRESC200611
    NOLOGGING
    TABLESPACE PRESC_PARTITION_23,
    PARTITION PRESC200612
    NOLOGGING
    TABLESPACE PRESC_PARTITION_24,
    PARTITION PRESC200701
    NOLOGGING
    TABLESPACE PRESC_PARTITION_25,
    PARTITION PRESC200702
    NOLOGGING
    TABLESPACE PRESC_PARTITION_26,
    PARTITION PRESC200703
    NOLOGGING
    TABLESPACE PRESC_PARTITION_27,
    PARTITION PRESC200704
    NOLOGGING
    TABLESPACE PRESC_PARTITION_28,
    PARTITION PRESC200705
    NOLOGGING
    TABLESPACE PRESC_PARTITION_29
    NOPARALLEL;

  • Explain Plan changed using "IN"

    Hi ,
    I am using one of the query as below
    select a.x, b.y, c.z from a,b,c
    where
    a.x in ( select x from temp where col=b.y)
    i checked explain plan this query is going to access full table x
    i have index on x for temp table.
    i need to check b.y in subquery as parameter and that subquery result i have to use as first main query's where criteria.
    using function i can get only one record at time.
    if anyone have any idea how to solve.
    TIA

    when i use = instead of "IN" below is the explain plan from TOAD
    Operation     Object Name     Rows     Bytes     Cost     Object Node     In/Out     PStart     PStop
    SELECT STATEMENT Optimizer Mode=RULE                                        
    SORT UNIQUE                                        
    CONCATENATION                                        
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    TABLE ACCESS BY INDEX ROWID     JOB_DETAIL_LINES                                   
    INDEX UNIQUE SCAN     PK_JOT                                   
    TABLE ACCESS BY INDEX ROWID     BULK_BOL                                   
    INDEX RANGE SCAN     BULK_BOL_N1                                   
    TABLE ACCESS BY INDEX ROWID     BULK_SKID                                   
    INDEX RANGE SCAN     BULK_SKID_N1                                   
    TABLE ACCESS BY INDEX ROWID     DVD_DISC_PRINT_CARTON                                   
    INDEX RANGE SCAN     DVD_DISC_PRINT_CARTON_N2                                   
    TABLE ACCESS BY INDEX ROWID     DVD_DISC_PRINT_SUPPLY                                   
    INDEX UNIQUE SCAN     DVD_DISC_PRINT_SUPPLY_PK                                   
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    TABLE ACCESS BY INDEX ROWID     JOB_DETAIL_LINES                                   
    INDEX UNIQUE SCAN     PK_JOT                                   
    TABLE ACCESS BY INDEX ROWID     BULK_BOL                                   
    INDEX RANGE SCAN     BULK_BOL_N1                                   
    TABLE ACCESS BY INDEX ROWID     BULK_SKID                                   
    INDEX RANGE SCAN     BULK_SKID_N1                                   
    TABLE ACCESS BY INDEX ROWID     DVD_DISC_PRINT_CARTON                                   
    INDEX RANGE SCAN     DVD_DISC_PRINT_CARTON_N2                                   
    TABLE ACCESS BY INDEX ROWID     DVD_DISC_PRINT_SUPPLY                                   
    INDEX UNIQUE SCAN     DVD_DISC_PRINT_SUPPLY_PK                                   
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    TABLE ACCESS BY INDEX ROWID     JOB_DETAIL_LINES                                   
    INDEX UNIQUE SCAN     PK_JOT                                   
    TABLE ACCESS BY INDEX ROWID     BULK_BOL                                   
    INDEX RANGE SCAN     BULK_BOL_N1                                   
    TABLE ACCESS BY INDEX ROWID     BULK_SKID                                   
    INDEX RANGE SCAN     BULK_SKID_N1                                   
    TABLE ACCESS BY INDEX ROWID     DVD_DISC_PRINT_CARTON                                   
    INDEX RANGE SCAN     DVD_DISC_PRINT_CARTON_N2                                   
    TABLE ACCESS BY INDEX ROWID     DVD_DISC_PRINT_SUPPLY                                   
    INDEX UNIQUE SCAN     DVD_DISC_PRINT_SUPPLY_PK                                   
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    TABLE ACCESS BY INDEX ROWID     BULK_BOL                                   
    INDEX RANGE SCAN     BULK_BOL_N1                                   
    TABLE ACCESS BY INDEX ROWID     BULK_SKID                                   
    INDEX RANGE SCAN     BULK_SKID_N1                                   
    TABLE ACCESS BY INDEX ROWID     DVD_DISC_PRINT_CARTON                                   
    INDEX RANGE SCAN     DVD_DISC_PRINT_CARTON_N2                                   
    TABLE ACCESS BY INDEX ROWID     DVD_DISC_PRINT_SUPPLY                                   
    INDEX UNIQUE SCAN     DVD_DISC_PRINT_SUPPLY_PK                                   
    TABLE ACCESS BY INDEX ROWID     JOB_DETAIL_LINES                                   
    INDEX UNIQUE SCAN     PK_JOT                                   
    when i use "IN" below is the explain plan from TOAD
    Operation     Object Name     Rows     Bytes     Cost     Object Node     In/Out     PStart     PStop
    SELECT STATEMENT Optimizer Mode=RULE                                        
    SORT UNIQUE                                        
    FILTER                                        
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    NESTED LOOPS                                        
    TABLE ACCESS FULL     JOB_DETAIL_LINES                                   
    TABLE ACCESS BY INDEX ROWID     BULK_BOL                                   
    INDEX RANGE SCAN     BULK_BOL_N1                                   
    TABLE ACCESS BY INDEX ROWID     BULK_SKID                                   
    INDEX RANGE SCAN     BULK_SKID_N1                                   
    TABLE ACCESS BY INDEX ROWID     DVD_DISC_PRINT_CARTON                                   
    INDEX RANGE SCAN     DVD_DISC_PRINT_CARTON_N2                                   
    TABLE ACCESS BY INDEX ROWID     DVD_DISC_PRINT_SUPPLY                                   
    INDEX UNIQUE SCAN     DVD_DISC_PRINT_SUPPLY_PK                                   
    INDEX UNIQUE SCAN     PK_JOT

  • Oracle not using its own explain plan

    When I run a simple select query on an indexed column on a large (30 million records) table oracle creates a plan using the indexed column and at a cost of 4. However, what it actually does is do a table scan (I can see this in the 'Long Operations' tab in OEM).
    The funny thing is that I have the same query in a ADO application and when the query is run from there, the same plan is created but no table scan is done - and the query returns in less than a second. However, with the table scan it is over a minute.
    When run through SQL plus Oracle creates a plan including the table scan at a cost of 19030.
    In another (dot net) application I used the: "Alter session set optimizer_index_caching=100" and "Alter session set optimizer_index_cost_adj=10" to try to force the optimizer to use the index. It creates the expected plan, but still does the table scan.
    The query is in the form of:
    "Select * from tab where indexedcol = something"
    Im using Oracle 9i 9.2.0.1.0
    Any ideas as I'm completely at a loss?

    Hello
    It sounds to me like this has something to do with bind variable peeking which was introduced in 9i. If the predicate is
    indexedcolumn = :bind_variablethe first time the query is parsed by oracle, it will "peek" at the value in the bind variable and see what it is and will generate an execution plan based on this. That same plan will be used for matching SQL.
    If you use a litteral, it will generate the plan based on that, and will generate a separate plan for each litteral you use (depending on the value of the cursor_sharing initialisation parameter).
    This can cause there to be a difference between the execution plan seen when issuing EXPLAIN PLAN FOR, and the actual exectuion plan used when the query is run.
    Have a look at the following example:
    tylerd@DEV2> CREATE TABLE dt_test_bvpeek(id number, col1 number)
      2  /
    Table created.
    Elapsed: 00:00:00.14
    tylerd@DEV2> INSERT
      2  INTO
      3      dt_test_bvpeek
      4  SELECT
      5      rownum,
      6      CASE
      7          WHEN MOD(rownum, 5) IN (0,1,2,3) THEN
      8              1
      9          ELSE
    10              MOD(rownum, 5)
    11          END
    12      END
    13  FROM
    14      dual
    15  CONNECT BY
    16      LEVEL <= 100000
    17  /
    100000 rows created.
    Elapsed: 00:00:00.81
    tylerd@DEV2> select count(*), col1 from dt_test_bvpeek group by col1
      2  /
      COUNT(*)       COL1
         80000          1
         20000          4
    2 rows selected.
    Elapsed: 00:00:00.09
    tylerd@DEV2> CREATE INDEX dt_test_bvpeek_i1 ON dt_test_bvpeek(col1)
      2  /
    Index created.
    Elapsed: 00:00:00.40
    tylerd@DEV2> EXEC dbms_stats.gather_table_stats( ownname=>USER,-
    tabname=>'DT_TEST_BVPEEK',-
    method_opt=>'FOR ALL INDEXED COLUMNS SIZE 254',-
    cascade=>TRUE -
    );PL/SQL procedure successfully completed.
    Elapsed: 00:00:00.73
    tylerd@DEV2> EXPLAIN PLAN FOR
      2  SELECT
      3      *
      4  FROM
      5      dt_test_bvpeek
      6  WHERE
      7      col1 = 1
      8  /
    Explained.
    Elapsed: 00:00:00.01
    tylerd@DEV2> SELECT * FROM TABLE(DBMS_XPLAN.display)
      2  /
    PLAN_TABLE_OUTPUT
    Plan hash value: 2611346395
    | Id  | Operation         | Name           | Rows  | Bytes | Cost (%CPU)| Time     |
    |   0 | SELECT STATEMENT  |                | 78728 |   538K|    82  (52)| 00:00:01 |
    |*  1 |  TABLE ACCESS FULL| DT_TEST_BVPEEK | 78728 |   538K|    82  (52)| 00:00:01 |
    Predicate Information (identified by operation id):
       1 - filter("COL1"=1)
    13 rows selected.
    Elapsed: 00:00:00.06The execution plan for col1=1 was chosen because oracle was able to see that based on the statistics, col1=1 would result in most of the rows from the table being returned.
    tylerd@DEV2> EXPLAIN PLAN FOR
      2  SELECT
      3      *
      4  FROM
      5      dt_test_bvpeek
      6  WHERE
      7      col1 = 4
      8  /
    Explained.
    Elapsed: 00:00:00.00
    tylerd@DEV2> SELECT * FROM TABLE(DBMS_XPLAN.display)
      2  /
    PLAN_TABLE_OUTPUT
    Plan hash value: 3223879139
    | Id  | Operation                   | Name              | Rows  | Bytes | Cost (%CPU)| Time     |
    |   0 | SELECT STATEMENT            |                   | 21027 |   143K|    74  (21)| 00:00:01 |
    |   1 |  TABLE ACCESS BY INDEX ROWID| DT_TEST_BVPEEK    | 21027 |   143K|    74  (21)| 00:00:01 |
    |*  2 |   INDEX RANGE SCAN          | DT_TEST_BVPEEK_I1 | 21077 |       |    29  (28)| 00:00:01 |
    Predicate Information (identified by operation id):
       2 - access("COL1"=4)
    14 rows selected.
    Elapsed: 00:00:00.04This time, the optimiser was able to see that col1=4 would result in far fewer rows so it chose to use an index. Look what happens however when we use a bind variable with EXPLAIN PLAN FOR - especially the number of rows the optimiser estimates to be returned from the table
    tylerd@DEV2> var an_col1 NUMBER
    tylerd@DEV2> exec :an_col1:=1;
    PL/SQL procedure successfully completed.
    Elapsed: 00:00:00.00
    tylerd@DEV2>
    tylerd@DEV2> EXPLAIN PLAN FOR
      2  SELECT
      3      *
      4  FROM
      5      dt_test_bvpeek
      6  WHERE
      7      col1 = :an_col1
      8  /
    Explained.
    Elapsed: 00:00:00.01
    tylerd@DEV2> SELECT * FROM TABLE(DBMS_XPLAN.display)
      2  /
    PLAN_TABLE_OUTPUT
    Plan hash value: 2611346395
    | Id  | Operation         | Name           | Rows  | Bytes | Cost (%CPU)| Time     |
    |   0 | SELECT STATEMENT  |                | 49882 |   340K|   100  (60)| 00:00:01 |
    |*  1 |  TABLE ACCESS FULL| DT_TEST_BVPEEK | 49882 |   340K|   100  (60)| 00:00:01 |
    Predicate Information (identified by operation id):
       1 - filter("COL1"=TO_NUMBER(:AN_COL1))
    13 rows selected.
    Elapsed: 00:00:00.04
    tylerd@DEV2>
    tylerd@DEV2> exec :an_col1:=4;
    PL/SQL procedure successfully completed.
    Elapsed: 00:00:00.01
    tylerd@DEV2>
    tylerd@DEV2> EXPLAIN PLAN FOR
      2  SELECT
      3      *
      4  FROM
      5      dt_test_bvpeek
      6  WHERE
      7      col1 = :an_col1
      8  /
    Explained.
    Elapsed: 00:00:00.01
    tylerd@DEV2> SELECT * FROM TABLE(DBMS_XPLAN.display)
      2  /
    PLAN_TABLE_OUTPUT
    Plan hash value: 2611346395
    | Id  | Operation         | Name           | Rows  | Bytes | Cost (%CPU)| Time     |
    |   0 | SELECT STATEMENT  |                | 49882 |   340K|   100  (60)| 00:00:01 |
    |*  1 |  TABLE ACCESS FULL| DT_TEST_BVPEEK | 49882 |   340K|   100  (60)| 00:00:01 |
    Predicate Information (identified by operation id):
       1 - filter("COL1"=TO_NUMBER(:AN_COL1))
    13 rows selected.
    Elapsed: 00:00:00.07For both values of the bind variable, the optimiser has no idea what the value will be so it has to make a calculation based on a formula which results in it estimating that the query will return roughly half of the rows in the table, and so it chooses a full scan.
    Now when we actually run the query, the optimiser can take advantage of bind variable peeking and have a look at the value the first time round and base the execution plan on that:
    tylerd@DEV2> exec :an_col1:=1;
    PL/SQL procedure successfully completed.
    Elapsed: 00:00:00.00
    tylerd@DEV2> SELECT
      2      *
      3  FROM
      4      dt_test_bvpeek
      5  WHERE
      6      col1 = :an_col1
      7  /
    80000 rows selected.
    Elapsed: 00:00:10.98
    tylerd@DEV2> SELECT prev_sql_id FROM v$session WHERE audsid=SYS_CONTEXT('USERENV','SESSIONID')
      2  /
    PREV_SQL_ID
    9t52uyyq67211
    1 row selected.
    Elapsed: 00:00:00.00
    tylerd@DEV2> SELECT
      2      operation,
      3      options,
      4      object_name
      5  FROM
      6      v$sql_plan
      7  WHERE
      8      sql_id = '9t52uyyq67211'
      9  /
    OPERATION                      OPTIONS                        OBJECT_NAME
    SELECT STATEMENT
    TABLE ACCESS                   FULL                           DT_TEST_BVPEEK
    2 rows selected.
    Elapsed: 00:00:00.03It saw that the bind variable value was 1 and that this would return most of the rows in the table so it chose a full scan.
    tylerd@DEV2> exec :an_col1:=4
    PL/SQL procedure successfully completed.
    Elapsed: 00:00:00.00
    tylerd@DEV2> SELECT
      2      *
      3  FROM
      4      dt_test_bvpeek
      5  WHERE
      6      col1 = :an_col1
      7  /
    20000 rows selected.
    Elapsed: 00:00:03.50
    tylerd@DEV2> SELECT prev_sql_id FROM v$session WHERE audsid=SYS_CONTEXT('USERENV','SESSIONID')
      2  /
    PREV_SQL_ID
    9t52uyyq67211
    1 row selected.
    Elapsed: 00:00:00.00
    tylerd@DEV2> SELECT
      2      operation,
      3      options,
      4      object_name
      5  FROM
      6      v$sql_plan
      7  WHERE
      8      sql_id = '9t52uyyq67211'
      9  /
    OPERATION                      OPTIONS                        OBJECT_NAME
    SELECT STATEMENT
    TABLE ACCESS                   FULL                           DT_TEST_BVPEEK
    2 rows selected.
    Elapsed: 00:00:00.01Even though the value of the bind variable changed, the optimiser saw that it already had a cached version of the sql statement along with an execution plan, so it used that rather than regenerating the plan. We can check the reverse of this by causing the statement to be invalidated and re-parsed - there's lots of ways, but I'm just going to rename the table:
    Elapsed: 00:00:00.03
    tylerd@DEV2> alter table dt_test_bvpeek rename to dt_test_bvpeek1
      2  /
    Table altered.
    Elapsed: 00:00:00.01
    tylerd@DEV2>
    20000 rows selected.
    Elapsed: 00:00:04.81
    tylerd@DEV2> SELECT prev_sql_id FROM v$session WHERE audsid=SYS_CONTEXT('USERENV','SESSIONID')
      2  /
    PREV_SQL_ID
    6ztnn4fyt6y5h
    1 row selected.
    Elapsed: 00:00:00.00
    tylerd@DEV2> SELECT
      2      operation,
      3      options,
      4      object_name
      5  FROM
      6      v$sql_plan
      7  WHERE
      8      sql_id = '6ztnn4fyt6y5h'
      9  /
    OPERATION                      OPTIONS                        OBJECT_NAME
    SELECT STATEMENT
    TABLE ACCESS                   BY INDEX ROWID                 DT_TEST_BVPEEK1
    INDEX                          RANGE SCAN                     DT_TEST_BVPEEK_I1
    3 rows selected.
    80000 rows selected.
    Elapsed: 00:00:10.61
    tylerd@DEV2> SELECT prev_sql_id FROM v$session WHERE audsid=SYS_CONTEXT('USERENV','SESSIONID')
      2  /
    PREV_SQL_ID
    6ztnn4fyt6y5h
    1 row selected.
    Elapsed: 00:00:00.01
    tylerd@DEV2> SELECT
      2      operation,
      3      options,
      4      object_name
      5  FROM
      6      v$sql_plan
      7  WHERE
      8      sql_id = '6ztnn4fyt6y5h'
      9  /
    OPERATION                      OPTIONS                        OBJECT_NAME
    SELECT STATEMENT
    TABLE ACCESS                   BY INDEX ROWID                 DT_TEST_BVPEEK1
    INDEX                          RANGE SCAN                     DT_TEST_BVPEEK_I1
    3 rows selected.This time round, the optimiser peeked at the bind variable the first time the statement was exectued and found it to be 4, so it based the execution plan on that and chose an index range scan. When the statement was executed again, it used the plan it had already executed.
    HTH
    David

  • [8i] Can someone help me on using explain plan, tkprof, etc.?

    I am trying to follow the instructions at When your query takes too long ...
    I am trying to figure out why a simple query takes so long.
    The query is:
    SELECT COUNT(*) AS tot_rows FROM my_table;It takes a good 5 minutes or so to run (best case), and the result is around 22 million (total rows).
    My generic username does not (evidently) allow access to PLAN_TABLE, so I had to log on as SYSTEM to run explain plan. In SQL*Plus, I typed in:
    explain plan for (SELECT COUNT(*) AS tot_rows FROM my_table);and the response was "Explained."
    Isn't this supposed to give me some sort of output, or am I missing something?
    Then, the next step in the post I linked is to use tkprof. I see that it says it will output a file to a path specified in a parameter. The only problem is, I don't have access to the db's server. I am working remotely, and do not have any way to remotely (or directly) access the db server. Is there any way to have the file output to my local machine, or am I just S.O.L.?

    SomeoneElse used "create table as" (CTAS), wich automatically gathers the stats. You can see the differende before and after stats clearly in this example.
    This is the script:
    drop table ttemp;
    create table ttemp (object_id number not null, owner varchar2(30), object_name varchar2(200));
    alter table ttemp add constraint ttemp_pk primary key (object_id);
    insert into ttemp
    select object_id, owner, object_name
    from dba_objects
    where object_id is not null;
    set autotrace on
    select count(*) from ttemp;
    exec dbms_stats.gather_table_stats('PROD','TTEMP');
    select count(*) from ttemp;And the result:
    Table dropped.
    Table created.
    Table altered.
    46888 rows created.
      COUNT(*)
         46888
    1 row selected.
    Execution Plan
               SELECT STATEMENT Optimizer Mode=CHOOSE
       1         SORT AGGREGATE
       2    1      TABLE ACCESS FULL PROD.TTEMP
    Statistics
              1  recursive calls
              1  db block gets
            252  consistent gets
              0  physical reads
            120  redo size
              0  PX remote messages sent
              0  PX remote messages recv'd
              0  buffer is pinned count
              0  workarea memory allocated
              4  workarea executions - optimal
              1  rows processed
    PL/SQL procedure successfully completed.
      COUNT(*)
         46888
    1 row selected.
    Execution Plan
               SELECT STATEMENT Optimizer Mode=CHOOSE (Cost=4 Card=1)
       1         SORT AGGREGATE (Card=1)
       2    1      INDEX FAST FULL SCAN PROD.TTEMP_PK (Cost=4 Card=46 K)
    Statistics
              1  recursive calls
              2  db block gets
            328  consistent gets
              0  physical reads
           8856  redo size
              0  PX remote messages sent
              0  PX remote messages recv'd
              0  buffer is pinned count
              0  workarea memory allocated
              4  workarea executions - optimal
              1  rows processed

  • Using explain plan

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    I want to know what are the important factors that we should emphasize to optimize a SQL query.
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