Question about connection pooling

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1

Hi,
Imagine I have two packages are execute simultanously.
Each of them execute adapters which use the same connection in Adapter connections.
The adapter connection use connection pool (for instance with a maximum of 10 connections).

My package 1 use an adapter (adapter1) which is an insert in database which can take some minutes
My package 2 use an adapter (adapter2) which is a select in the same table (and maybe the same records than adapter 1) which is very speed.

My connection have TransactionIsolation = 1 (read uncommit) which mean if you read, you can read a record which is update in same time without waiting the update statement. (however, the record you read is uncommited).

Imagine now, it exists for instance 1 sec between execution of adapters in package 1 and adapter in package 2. Which explain even if it is simultaenous, adapter in package 1 is executed before adapter in package 2.

My question is the following :
Connection pool execute each connection simultaneously or sequently.

Means in my case adapter in package 2 will wait adapter in package 1 is finished to be executed even if isolationlevel = 1

2

Statements are executed not by the connection pool but by the threads within the IS and within the DB. Connection pool just provides connections to the DB and sets them up accordingly.

So I’d say, the number of connections involved depends on whether the thread that executes the adapter 1 releases the connection back to the pool before a connection is requested by the thread that executes the adapter 2.

The DB may also pose some serialization onto statement execution. But modern DBs are usually quite good at paralellizing jobs so I woudn’t expect a bottleneck there.

If you explain the nackground of your question, we might give a more meaningful answer.