Is it allowed to drop histograms on sys tables

Nenad Noveljic

I'd like to drop a histogram on WRI$_OPTSTAT_SYNOPSIS_HEAD$ to get a better execution plan.

Further, I'd like to set it as a table preference not to create a histogram on this table any more.

I'm I allowed to do that?

Best regards,

Nenad

Jonathan Lewis

I can think of no good reason why you shouldn't.

In principle the histogram might disappear spontaneously the next time you (auto-Oracle) gathers stats on the table, so the presence or absence of the histogram has no material impact on the nature of the table, only on the optimization of certain queries. So I'd sest the preference and gather stats (but I'd test on a sandbox database first).

Regards

Jonathan Lewis

Jonathan Lewis

I can think of no good reason why you shouldn't.

In principle the histogram might disappear spontaneously the next time you (auto-Oracle) gathers stats on the table, so the presence or absence of the histogram has no material impact on the nature of the table, only on the optimization of certain queries. So I'd sest the preference and gather stats (but I'd test on a sandbox database first).

Regards

Jonathan Lewis

Nenad Noveljic

Thank you, Jonathan.