Re: [ANNOUNCE] IMCS: In Memory Columnar Store for PostgreSQL - Mailing list pgsql-hackers

From james
Subject Re: [ANNOUNCE] IMCS: In Memory Columnar Store for PostgreSQL
Date
Msg-id 52CB1A49.5060700@mansionfamily.plus.com
Whole thread Raw
In response to Re: [ANNOUNCE] IMCS: In Memory Columnar Store for PostgreSQL  (Amit Kapila <amit.kapila16@gmail.com>)
Responses Re: [ANNOUNCE] IMCS: In Memory Columnar Store for PostgreSQL  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
On 06/01/2014 04:20, Amit Kapila wrote:
> Duplicate handle should work, but we need to communicate the handle
> to other process using IPC.
Only if the other process needs to use it.  The IPC is not to transfer 
the handle to
the other process, just to tell it which slot in its handle table 
contains the handle.
If you just want to ensure that its use-count never goes to zero, the 
receiver does
not need to know what the handle is.

However ...

The point remains that you need to duplicate it into every process that 
might
want to use it subsequently, so it makes sense to DuplicateHandle into the
parent, and then to advertise that  handle value publicly so that other 
child
processes can DuplicateHandle it back into their own process.

The handle value can change so you also need to refer to the handle in the
parent and map it in each child to the local equivalent.




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