CONCAT function
Hello,
The pg_catalog.concat() is defined as STABLE function.
As per my understanding a STABLE function cannot modify the database and is
guaranteed to return the same results given the same arguments for all rows
within a single statement.
Example:
current_timestamp family of functions qualify as stable, since their values
do not change within a transaction.
An IMMUTABLE function cannot modify the database and is guaranteed to return
the same results given the same arguments forever.
why was STABLE preferred for concat() over IMMUTABLE?
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Regards,
Vinayak,
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Vinayak <vinpokale@gmail.com> writes:
The pg_catalog.concat() is defined as STABLE function.
why was STABLE preferred for concat() over IMMUTABLE?
concat() invokes datatype output functions, which are not necessarily
immutable. An easy example is that timestamptz_out's results depend
on the TimeZone setting.
regards, tom lane
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Thank you for reply.
concat() invokes datatype output functions, which are not necessarily
immutable. An easy example is that timestamptz_out's results depend
on the TimeZone setting.
I understood.
-----
Regards,
Vinayak,
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