Sybase DC38133-01-0902-01 manual To those when tuning the incoming-message polling frequency

		Chapter 10. SQL Remote Administration
Issues to consider	The issues to consider when tuning the message-sending process are similar
	to those when tuning the incoming-message polling frequency:
	♦ Regular messages	Your choices dictate how often updates are sent to
	remote databases.
	♦ Resend requests	When a remote user requests that a message be

resent, the Message Agent needs to take special action that can interrupt regular message sending. You can control the urgency with which these resend requests are processed.

♦ Number and size of messages If you send messages very frequently, there is more chance of small messages being sent. Sending messages less frequently allows more instructions to be grouped in a single message. If a large number of small messages is a concern for your message system, then you may have to avoid using very small polling periods.

☞ For more information on tuning polling for the incoming-messages, see “Tuning incoming message polling” on page 230 .

Polling interval

You control the interval to wait between polls for more data from the transaction log to send using the -sdoption, which has a default of one minute. The following example sets the polling interval to 30 seconds:

dbremote -sd 30s ...

Alternatively, you can poll less frequently, as in the following command line, which polls every five minutes:

dbremote -sd 5

Setting a very small interval may have some detrimental impact on overall system throughput, for the following reasons:

♦Too-frequent polling produces many short messages. If the message load places a strain on your message system, throughput could be affected.

Setting larger intervals may provide a better overall throughput of messages in your system, at the cost of waiting somewhat longer for each message to be applied. In many SQL Remote installations, optimizing turnaround time is not the primary concern.

Resending messages

When a user requests that a message be resent, the message has to be retrieved from early in the transaction log. Going back in the transaction log

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