If slowness saving changes is faced in both Developer client and Analyst tool, I would suggest to review MRS java options. What is the MRS max heap space value? You may want to try increasing MRS max heap space in admin console and try again after recycling MRS.
In addition to Juan response, you mentioned the data preview on an object takes more than 10 minutes. Let me know if this is same for all type of PDOs like Flat file, relational etc or specific to only flat file or only relational? You might need to increase the heap size as well if it is set to default value.
You can also collect stacks on the MRS to check if there is any issues on the MRS database side. In order to analyze the stacks or troubleshoot the issue, please raise case with Informatica Support team or if possible collect few stacks on MRS and attach it here so that someone can review and suggest you accordingly.
Is the delay in changes etc. a sudden issue or has it been getting gradually slower over time?
If it's a sudden issue it suggests something may have changed on your Domain server, the network or the database hosting the MRS e.g. server relocation, software upgrades tec.
If the increase in response time has been gradual it suggests the MRS has been getting bigger over time causing requests for metadata to take longer. In this instance you can try increase memory as Juan mentioned above, but a review of the MRS data to remove any test mappings etc. may also help speed up the response time.
Give us an example of slowness - I assume it is most likely a SQL query mapping.
- Provide your Informatica setting (mem, cpu per node), kernel ulimits
- it is a grid or a standalone ?
In that case your problem is on database side, check the tables in the SQL query and work with the DBA to add missing index.
DBAs should know which missing index is required.
- what is your DB (Oracle, MySQL ?)
As mentioned you could increase your JAVA heap size for MRS, DIS as well.
Please check the KB for performance DIS , MRS, there are PDF guide.
hope this helps!