Confirm whether you have this issue:

Acquire a count of the SCORInventory data type in the SCOR_DATA_CHANNEL table using the following SQL queries:

Query 1
Select DATA_TYPE, count(*) as COUNT from SCOR_DATA_CHANNEL group by DATA_TYPE;
 

	DATA_TYPE	COUNT
1	SCORCommand Response	1
2	SCORDiag	98
3	SCORInventory	758015

NOTE: A high COUNT for the SCORInventory data type suggests that the inventory-diff or a Pull Inventory Client Task was scheduled for many hosts simultaneously.

Query 2
Select DATA_TYPE, count(distinct TRANSACTION_ID) as TX_COUNT from SCOR_DATA_CHANNEL group by DATA_TYPE;
 

	DATA_TYPE	TX_COUNT
1	SCORInventory	758015
2	SCORCommandResponse	1
3	SCORDiag	98

NOTE: A high TX_COUNT for the SCORInventory data type confirms that the issue is because of inventory-diff. If the count for SCORInventory from Query1 is high and Query2 is low, a Pull Inventory Client Task scheduled for many hosts simultaneously might be the cause.

 

Workaround:
Switch off inventory-diff and run the SC: Pull Inventory Client Task on a limited number of hosts per day.

IMPORTANT: To understand the implications of disabling the inventory-diff feature, see KB81702 - Implications of disabling "Inventory-Diff" for Application Control 6.x.

To switch off Solidcore inventory-diff:

As a best practice, we recommend that you schedule the Pull Inventory Client Task for 300 or fewer hosts per day. Determine whether all SCORInventory data is being processed from the SCOR_DATA_CHANNEL table. Gradually increase the number of hosts until it reaches the maximum. The maximum value is reached when the SCORInventory data type takes more than 24 hours to process.

You can also enable debug logging on ePO and collect MERs. The debug information indicates how long the thread takes to process the inventory from a single host.
 

Example
Log at the start of processing:

Log at the end of processing:

2013-10-29 00:56:40,961 DEBUG [mfs:pool-2-thread-13] inventory.InventoryPullInternalTask  - Inv Pull done for AgentGuid: 652F9790-18C9-418D-AD6C-6C786DE4FED3