Well, I can recommend Jonathan's Scratchpad blog. Jonathan wrote several
excellent articles about the in-memory option. Two of them are listed below:
https://jonathanlewis.wordpress.com/2015/01/26/in-memory-db/
https://jonathanlewis.wordpress.com/category/oracle/12c/in-memory/
The list is by no means exhaustive. However, what I noticed is that
in-memory option, well, devours memory. Who would expect that? Even with
the highest degree of compression you need approximately 20% of table
size to store a table into memory. For large tables, that is out of the
question. In addition to that, in-memory option is not very frequently
used so you may encounter bugs. I have recently encountered a bug with
latching with result cache. RC latch has killed my application. The use
was there, the query was extracting the city and the state from the ZIP
code. The vast majority of transactions was from the New York City area,
so result cache made sense. Unfortunately, the application was doing
700+ TPS and result cache, instead of helping, killed the application.
That bug is pertinent for 12.1 and 12.2, it's fixed in the higher versions.
Since not many people use In-Memory, you don't know whether you will
encounter something like that. And yes, I tested the In-Memory option
and was disappointed with the amount of memory it needs. Who would
expect In-Memory option to devour memory?
On 4/15/21 12:10 PM, Jeff Chirco wrote:
Hey curious if any have the In-Memory option and would it be worth it? We are looking to increase our CPU footprint on our server and think about maybe trying to squeeze this in if the discount is right. Although this is the most expensive option. We are currently a small server, only 4cpu going to 8, but we also have a DR server which would stay on a 4cpu server but I know it also needs to be licensed.
What time of systems is it best for? Any good blogs on it?
Thanks,
