On: Ex-Facebookers launch MemSQL (YC W11) to make your...

[snissn]

MemSQL does not yet support JOINs on more than 2 tables. [1]

1. http://developers.memsql.com/docs/1b/sql/join.html

[chris_wot → snissn]

Nor transactions with more than one statement. And only read committed isolation level. [1]

1. http://developers.memsql.com/docs/1b/isolationlevel.html

[snissn → chris_wot]

This seems really confusing and like it might be a maintenance nightmare http://developers.memsql.com/docs/1b/memory.html

Do you need to ensure that all of your data fits in memory? It's easily possible to have ten gigs in your db but only need a small amount of it to be hot in ram. Does it take a really long time to restart if it has to warm all the data?

[chris_wot → snissn]

Good questions - no idea! Can one of the developers of MemSQL clarify this? How long does it take to startup a large database of several 100 GB?

[nikita → chris_wot]

Recovery on the system restart is going at the speed of hard disk.

[chris_wot → nikita]

Can you pin how much data from a table can be placed into memory, or does the whole table need to be placed in memory? I can see settings that limit the transaction log memory usage, but no way of reducing the actual amount of data in-memory.

[nikita → chris_wot]

The whole table has to fit in memory. RAM is getting very cheap, you can buy 1Tb for 12K today.

[genwin → nikita]

But for anyone who is renting the server, it's $$$$ monthly for a fraction of that.

[tintor → nikita]

Recovery on the system restart is going at the "sequential scan" speed of hard disk.

[nl → tintor]

The "sequential scan" speed of a generic SSD is pretty good. It's even better on something like FusionIO.