---- dataentry configoptions ----
type             : constant
name             : MESSAGEQUEUE_PREPARE
purpose          : Run the queue in a two-process way
allowed          : true false 0 1
default          : 0
status_s         : 
category         : queue processing
----

This option will initially mark all subscribers that need to receive the campaign as "todo" in the table and then start processing on all the "todo" entries.

It may save a little on SQL time when you have a large amount of subscribers, as the query to search for subscribers is run fewer times.

Comparison:

When MESSAGEQUEUE_PREPARE is 0, each batch of messages is processed as
follows:

  - Find all subscribers who need to receive the campaign and haven't received it yet
  - Dispatch the campaign to some subscribers (batch size settings determine how many)

When MESSAGEQUEUE_PREPARE is 1, the first batch of messages is processed
as follows:

  - Find all subscribers who need to receive the campaign (as in step 1 above)
  - Mark the found subscribers as "todo" in the database
  - Send some of the marked subscribers the campaign

Then for all subsequent batches:

  - Find subscribers marked "todo"
  - Send some of them the campaign (batch size settings determine how many)

See also [[MAX_SENDPROCESSES]]