Improve company productivity with a Business Account.Sign Up

  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 238
  • Last Modified:

In-Memory Database

I have a 3 tier Application. In the middle tier, which is in the form of active X Exe, i want to get data into the middle tier from the database and maintain it in-memory till the exe is being used.
Please suggest how to maintain the data other than disconnected recordsets
1 Solution
Store it in arrays?
Memory databases are extremely powerful when used correctly - I use the concept in my current application and the performance is amazing compared to fetches from the database each time.

I can't really go into too much detail here, as my current app's implementation is very complex, but here are a few general things I've come across with cacheing data in memory:

MTS - state is not maintained, so your data cache tier cannot use MTS.

Data synchronisation across machines - If you have data in memory, and it's changed on one machine, the data needs to be refreshed somehow. I used a mechanism using sockets to broadcast data update messages across all client workstations.

My data layer translates recordsets into collections of objects - it's not the fastest way to do things, but it makes coding against the objects very easy. I wrote a small 'generator' program to produce VB code for the data tier objects, their collection, and the general access/synchronisation code based on a database table.

Microsoft are interested in memory databases - SQL server is scheduled to have some kind of client cacheing in the near future, so it might be worth waiting or trying to find out how it's going to be done before coding your own version.

Garbage collection - Unless your DB is small, don't try and keep everything in memory. Use a garbage collection technique to 'forget' data which is not being used. You can use a reference count (like COM), a proper GC (like .net) or an alternative method (I use a callback interface to check if an object is still being referenced by an active object before removing it from the cache).

Keep up with what's happening at Experts Exchange!

Sign up to receive Decoded, a new monthly digest with product updates, feature release info, continuing education opportunities, and more.

Just curious, what do you have against disconnected recordsets?
<ping>.. Listening
aglAuthor Commented:

We have used disconnected recordsets in the application using collections along with it.But performance is hampered as we keep as many as 100000 records at a time in memory and using recordsets we have to scroll through each and every record to get to the one we want to process.
So we want a system where we can use sql queries(select,update,insert,delete) and get records in one shot rather than scrolling through them.

Why not use the filter property of the recordset.  With tht filter property, ADO searchs the records for you using the indexes that it retrieved from the database.  I assume the fields you want to search by are indexed fields.  By using disconnected recordsets and this property, you should have a in-memory db with good performance at the same time.

If this still doesn't give you the performance you need, then your only real choice is to convert the records into a sorted list that you can use a binary search on.  But of course you can actually do a binary search on a recordset also by using the move method and specifying the record to jump to.
Thank you for your interest in Expert’s Exchange. We hope that this information has assisted you in diagnosing your problem. Please award the experts who diligently helped you to find a solution (if any) or request a moderator to PAQ or delete this question. I will check back in seven days to see if a response was given. If not this will be turned over to a moderator for a decision. Thank you!

Your options are:

1. Accept a Comment As Answer (use the button next to the Expert's name).
2. Close the question if the information was not useful to you. You must tell the participants why you wish to do this, and allow for Expert response.
3. Ask Community Support to help split points between participating experts and include the details (expert name and point values to each).
4. Delete the question. Again, you must tell the other participants why you wish to do this, and only Moderators can take this action for you. Do not try to delete them directly if any comments exist, they will be pended and will not complete.

For special handling needs, please post a zero point question in the link below, include the question QID/link.

Please click this Help Desk link for Member Guidelines, Member Agreement and the Question/Answer process: Click you Member Profile to view your question history and keep them all current with updates as the collaboration effort continues.

PLEASE DO NOT AWARD THE POINTS TO ME. ------------> EXPERTS: Please leave any comments regarding this question here on closing recommendations if this item remains inactive another seven (7) days.


My following recommended disposition:

Points to andyclap

If you have any comment or objection to the recommendation, please leave it here.

EE Cleanup Volunteer

Per recommendation, force-accepted.

CS Moderator
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now