mds_Stores some times used 100% of CPU

As far as I understand all the above options limit functionality.

With the email indexing solution (assuming that is the problem) I expect problems when working with Gmail, as Gmail uses "tags" which translate to folders in the mail client. If an email message is tagged with more than one tag it will, by definition, be duplicated in the client, and if it is deleted on the client I don't know what kind of strange results I'll get on the server.

Removing folders from being indexed is also not a solution at all.

It just means indexing doesn't work properly, so we will not let it do much, but it is exactly on changing folders that search is most useful.

Is there no way to simply limiting the memory resources granted to spotlight indexing?

This seems to me like the most obvious and correct solution.

That means that Spotlight is indexing your Harddrive.

To switch off the indexing open a Terminal window and type:

sudo mdutil -a -i off

NB: You will be prompted to enter your admin password.

If you change your mind about Spotlight, and decide to give it another try, then it’s just as easy to switch back on as it was to switch off.

Again, in a terminal window type the following:

sudo mdutil -a -i on

NB: You will be prompted to enter your admin password.

I had the same problem. After months of memory pressure (100% mds_stores, processes paused frequently), I found the cure.

If your mail-account (hosted exchange or imap) contains a lot of duplicates - in my case thousands - spotlight indexing causes havoc. I assume, it is trying to compare all duplicates, so it can show them as one message. Duplicates may result from incomplete move/copy/delete or from receiving multiple copies of the same mail.

I used https://github.com/quentinsf/IMAPdedup to go through all folders and delete duplicates automatically. This compares message-IDs and/or headers.

After that, neither of my macs has seen memory pressure again - ever.

I hope this helps everyone that suffers from memory pressure as I did.

Hint: If your iOS mail app shows different unread counts for the same mail folders from your OS X mail app, this is a certain indication for duplicates. Same, if you iOS shows emails, while OS X mail shows an empty folder.

I tried disabling Spotlight in the Terminal and force quit the process in Activity Monitor, but mds_stores kept popping back up and climbing up the charts of memory use. It wasn't until I found the following link that I've gotten it to hover around 60 MBs for good.

http://9to5mac.com/2014/02/11/how-to-get-spotlight-processes-back-under-control- when-cpu-usage-goes-crazy/

In short, go to System Preferences -> Spotlight -> Privacy and start dragging and dropping all your frequently changing folders. Creative Cloud Files and my external hard drive dramatically reduced the CPU usage alone.

It looks to me like the solution given by Pencil_Neck is simpler and more useful.