Re: Why ORA-1555 snapshot too old.

Chuck.
The developer hasn't done

    'set transaction read only'
before the loop has he ?

I can't imagine any way that you can get ORA-1555 if you are correct in your statement that

> I know the RBS is not wrapping back on itself
> in that short of a time and it is not shrinking
> either.

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Jonathan Lewis
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Chuck wrote in message ...


>One of my developers is trying to query a 45g table that is

constantly being


>insert into. He wants to get a count of rows that meet a certain

criteria.


>Of couse he got ORA-1555 snapshot too old. I told him to query

smaller


>sections of the table and total up the counts for the individual

sections so


>he wrote a PL/SQL block to do that. It loops through table selecting

1000


>rows at a time. Each of these queries finishes in seconds but he is

still


>getting ora-1555 though. Why? According to Oracle's documentation

under the


>"set transaction" command they use"statement-level read consistency".

Isn't


>each separate execution of the select a new statement? I know the RBS

is not


>wrapping back on itself in that short of a time and it is not

shrinking


>either.

>