All plan generator plans in Oracle









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While reading Oracle SQL tuning guide I came across such a quote (you can find it in this chapter):




The plan generator explores various plans for a query block by trying out different access paths, join methods, and join orders.



Many plans are possible because of the various combinations that the database can use to produce the same result. The optimizer picks the plan with the lowest cost.



Figure 4-2 Optimizer Components



Figure 4-2 Optimizer Components




Is it possible somehow to get all these plans that were generated by plan generator?



Maybe there are standard PL/SQL packages for this or system views?










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  • No its not possible to get the intermediate plans generated whiling execution of a SQL in Oracle.
    – XING
    Nov 10 at 14:53










  • @XING Ok, thx. Maybe post it as an answer? I'll accept your answer then.
    – Oiale
    Nov 10 at 14:57






  • 1




    check the 10053 trace if you want to lear internals about query optimization. You can see there some of the alternatives that were thrown away
    – Marmite Bomber
    Nov 10 at 15:59











  • @MarmiteBomber Thx for the link!
    – Oiale
    Nov 11 at 13:27














up vote
3
down vote

favorite
1












While reading Oracle SQL tuning guide I came across such a quote (you can find it in this chapter):




The plan generator explores various plans for a query block by trying out different access paths, join methods, and join orders.



Many plans are possible because of the various combinations that the database can use to produce the same result. The optimizer picks the plan with the lowest cost.



Figure 4-2 Optimizer Components



Figure 4-2 Optimizer Components




Is it possible somehow to get all these plans that were generated by plan generator?



Maybe there are standard PL/SQL packages for this or system views?










share|improve this question























  • No its not possible to get the intermediate plans generated whiling execution of a SQL in Oracle.
    – XING
    Nov 10 at 14:53










  • @XING Ok, thx. Maybe post it as an answer? I'll accept your answer then.
    – Oiale
    Nov 10 at 14:57






  • 1




    check the 10053 trace if you want to lear internals about query optimization. You can see there some of the alternatives that were thrown away
    – Marmite Bomber
    Nov 10 at 15:59











  • @MarmiteBomber Thx for the link!
    – Oiale
    Nov 11 at 13:27












up vote
3
down vote

favorite
1









up vote
3
down vote

favorite
1






1





While reading Oracle SQL tuning guide I came across such a quote (you can find it in this chapter):




The plan generator explores various plans for a query block by trying out different access paths, join methods, and join orders.



Many plans are possible because of the various combinations that the database can use to produce the same result. The optimizer picks the plan with the lowest cost.



Figure 4-2 Optimizer Components



Figure 4-2 Optimizer Components




Is it possible somehow to get all these plans that were generated by plan generator?



Maybe there are standard PL/SQL packages for this or system views?










share|improve this question















While reading Oracle SQL tuning guide I came across such a quote (you can find it in this chapter):




The plan generator explores various plans for a query block by trying out different access paths, join methods, and join orders.



Many plans are possible because of the various combinations that the database can use to produce the same result. The optimizer picks the plan with the lowest cost.



Figure 4-2 Optimizer Components



Figure 4-2 Optimizer Components




Is it possible somehow to get all these plans that were generated by plan generator?



Maybe there are standard PL/SQL packages for this or system views?







sql oracle optimization






share|improve this question















share|improve this question













share|improve this question




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edited Nov 10 at 18:07









a_horse_with_no_name

285k45428526




285k45428526










asked Nov 10 at 14:24









Oiale

22617




22617











  • No its not possible to get the intermediate plans generated whiling execution of a SQL in Oracle.
    – XING
    Nov 10 at 14:53










  • @XING Ok, thx. Maybe post it as an answer? I'll accept your answer then.
    – Oiale
    Nov 10 at 14:57






  • 1




    check the 10053 trace if you want to lear internals about query optimization. You can see there some of the alternatives that were thrown away
    – Marmite Bomber
    Nov 10 at 15:59











  • @MarmiteBomber Thx for the link!
    – Oiale
    Nov 11 at 13:27
















  • No its not possible to get the intermediate plans generated whiling execution of a SQL in Oracle.
    – XING
    Nov 10 at 14:53










  • @XING Ok, thx. Maybe post it as an answer? I'll accept your answer then.
    – Oiale
    Nov 10 at 14:57






  • 1




    check the 10053 trace if you want to lear internals about query optimization. You can see there some of the alternatives that were thrown away
    – Marmite Bomber
    Nov 10 at 15:59











  • @MarmiteBomber Thx for the link!
    – Oiale
    Nov 11 at 13:27















No its not possible to get the intermediate plans generated whiling execution of a SQL in Oracle.
– XING
Nov 10 at 14:53




No its not possible to get the intermediate plans generated whiling execution of a SQL in Oracle.
– XING
Nov 10 at 14:53












@XING Ok, thx. Maybe post it as an answer? I'll accept your answer then.
– Oiale
Nov 10 at 14:57




@XING Ok, thx. Maybe post it as an answer? I'll accept your answer then.
– Oiale
Nov 10 at 14:57




1




1




check the 10053 trace if you want to lear internals about query optimization. You can see there some of the alternatives that were thrown away
– Marmite Bomber
Nov 10 at 15:59





check the 10053 trace if you want to lear internals about query optimization. You can see there some of the alternatives that were thrown away
– Marmite Bomber
Nov 10 at 15:59













@MarmiteBomber Thx for the link!
– Oiale
Nov 11 at 13:27




@MarmiteBomber Thx for the link!
– Oiale
Nov 11 at 13:27












1 Answer
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1
down vote



accepted










Typically you do not need to see all possible plans, but in some cases there is an interesting question, why does Oracle discard some plan and use an alternative one instead.



To answer this the ideal entry is the 10053 trace produced by Oracle.



There is a classical paper on this thema from Wolfgang Breitling which can be found here.



Also Jonathan Lewis in his Cost-Base Oracle Fundamentals dedicated a chapter 14 The 10053 Trace to this thema.



Google will for sure provide other references.



A word of warning. The 10053 is not the simplest stuff in Oracle context. Also in each release you may expect changes in the output. A good starting point to learn is to investigate a query that produces a different execution plan in two different environments. Simple take the 10053 trace in both databases and make a file diff and observe the difference. You will see, if there is a difference in the optimizer parameters, object or system statistics and how those changes have influence on the selection of the final execution plan.






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    up vote
    1
    down vote



    accepted










    Typically you do not need to see all possible plans, but in some cases there is an interesting question, why does Oracle discard some plan and use an alternative one instead.



    To answer this the ideal entry is the 10053 trace produced by Oracle.



    There is a classical paper on this thema from Wolfgang Breitling which can be found here.



    Also Jonathan Lewis in his Cost-Base Oracle Fundamentals dedicated a chapter 14 The 10053 Trace to this thema.



    Google will for sure provide other references.



    A word of warning. The 10053 is not the simplest stuff in Oracle context. Also in each release you may expect changes in the output. A good starting point to learn is to investigate a query that produces a different execution plan in two different environments. Simple take the 10053 trace in both databases and make a file diff and observe the difference. You will see, if there is a difference in the optimizer parameters, object or system statistics and how those changes have influence on the selection of the final execution plan.






    share|improve this answer
























      up vote
      1
      down vote



      accepted










      Typically you do not need to see all possible plans, but in some cases there is an interesting question, why does Oracle discard some plan and use an alternative one instead.



      To answer this the ideal entry is the 10053 trace produced by Oracle.



      There is a classical paper on this thema from Wolfgang Breitling which can be found here.



      Also Jonathan Lewis in his Cost-Base Oracle Fundamentals dedicated a chapter 14 The 10053 Trace to this thema.



      Google will for sure provide other references.



      A word of warning. The 10053 is not the simplest stuff in Oracle context. Also in each release you may expect changes in the output. A good starting point to learn is to investigate a query that produces a different execution plan in two different environments. Simple take the 10053 trace in both databases and make a file diff and observe the difference. You will see, if there is a difference in the optimizer parameters, object or system statistics and how those changes have influence on the selection of the final execution plan.






      share|improve this answer






















        up vote
        1
        down vote



        accepted







        up vote
        1
        down vote



        accepted






        Typically you do not need to see all possible plans, but in some cases there is an interesting question, why does Oracle discard some plan and use an alternative one instead.



        To answer this the ideal entry is the 10053 trace produced by Oracle.



        There is a classical paper on this thema from Wolfgang Breitling which can be found here.



        Also Jonathan Lewis in his Cost-Base Oracle Fundamentals dedicated a chapter 14 The 10053 Trace to this thema.



        Google will for sure provide other references.



        A word of warning. The 10053 is not the simplest stuff in Oracle context. Also in each release you may expect changes in the output. A good starting point to learn is to investigate a query that produces a different execution plan in two different environments. Simple take the 10053 trace in both databases and make a file diff and observe the difference. You will see, if there is a difference in the optimizer parameters, object or system statistics and how those changes have influence on the selection of the final execution plan.






        share|improve this answer












        Typically you do not need to see all possible plans, but in some cases there is an interesting question, why does Oracle discard some plan and use an alternative one instead.



        To answer this the ideal entry is the 10053 trace produced by Oracle.



        There is a classical paper on this thema from Wolfgang Breitling which can be found here.



        Also Jonathan Lewis in his Cost-Base Oracle Fundamentals dedicated a chapter 14 The 10053 Trace to this thema.



        Google will for sure provide other references.



        A word of warning. The 10053 is not the simplest stuff in Oracle context. Also in each release you may expect changes in the output. A good starting point to learn is to investigate a query that produces a different execution plan in two different environments. Simple take the 10053 trace in both databases and make a file diff and observe the difference. You will see, if there is a difference in the optimizer parameters, object or system statistics and how those changes have influence on the selection of the final execution plan.







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 13 at 21:24









        Marmite Bomber

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