shared pool problem

Hi,

I have a weird situation maybe some of you experts can explain it to me

We had some ORA-4031 errors. from the library cache dumps

I see the following line

*Chunk 70000007603f898 sz= 5696 R-freeable "library cache "
ds=70000008cac7798 *

to me that means there is 5696 bytes of recreatable free memory in library cache heap.

But the alert log at the same time shows

*ORA-04031: unable to allocate 4216 bytes of shared memory ("shared
pool","unknown object","sga heap(1,0)","library cache")*

So why is oracle not able to allocate 4216 bytes of memory when it has 5696 byte chunk of recreatable memory to flush out.

thanks
amit

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