GL reports on multiple ledgers

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Our client has close to 40 million journal lines across ledgers for a single period.

They want a BIP report where they will only pass the ledger set and choose all ledgers within it (approx 10-15 based on the ledger set). Few other parameters are on the line level DFF which stores a description.

Though the report fetches only 100 lines due to the dff filter it runs for 15-20 mins to complete.

Question 1: Is it advisable to run custom BIP reports on either Journal or balances on multiple ledgers? (On all the seeded reports ledger set and ledger are mandatory paramaters). is there any oracle doc id which suggests not to run on multiple ledgers at a time?