The major change in R12 is that there are no Sets of Books. Instead, there are subledgers that handle the transaction processing from other modules (AP, AR, FA, etc.). The Set of Books is replaced by the term Ledger. The column SET_OF_BOOKS_ID has been replaced with LEDGER_ID in all GL tables. The Subledger Accounting tables are in the XLA schema. The table GL.GL_Ledgers stores the information about the 4 C's: Currency, Chart of Accounts, Calendar, and [Accounting] Convention for each ledger. Subledger Accounting (SLA) uses a rules-based accounting engine that creates the GL accounting entries from transactions and events. Journal entries are created in the Subledger accounting and then transferred to the Oracle General Ledger.

Each subledger transaction that requires accounting is represented by complete and balanced subledger journal entry that is stored according to the common data model. The subledger accounting includes a posting engine that sums the contents of subledger tables and posts them to general ledger to provide a clear audit trail. The subledger accounting service is applicable to all products in R12 and succeeds other accounting engines including the Global Accounting Engine and Autoaccounting. Subledger accounting provides subledger tables and reports designed for compliance and accounting reconciliation that will replace "distribution" tables for these purposes. Distribution tables in Receivables, Assets, Project, and Procurement remain available and are deployed for other purposes.

The following entity diagram adapted from the Oracle Subledger Accounting Technical Reference Manual demonstrates the relationships between the transactions and the accounting ledgers.

All accounting is performed before the transfer to the General Ledger. The user defines rules and events to create the accounting entries. The subledgers post activity to the General Ledger through the Create Accounting process. The Distribution Link creates the accounting by applying accounting rules and loads the SLA and GL tables. Create Accounting can be done in Draft or Final mode. Create Accounting transfers the Final accounting journal entries to the GL from each process that calls it.

As a part of Subledger Accounting, new SLA tables XLA_AE_HEADERS, XLA_AE_LINES, and XLA_DISTRIBUTION_LINKS have been introduced. This means that an additional layer has been added at the subledger level. The Create Accounting process at the subledger level posts the data to the SLA tables.

The process looks like this:

The XLA.XLA_ HEADERS table stores subledger journal entries. There is a one-to-many relationship between accounting events and journal entry headers. The XLA_ LINES table stores subledger journal entry lines. There is a one-to-many relationship between subledger journal entry headers and subledger journal entry lines. XLA_DISTRIBUTION_LINKS stores the link between transactions and subledger journal entry lines. There is a one-to-many relationship between the subledger lines and distribution links. The transaction is stored in the XLA_DISTRIBUTION_LINKS table in the columns UNROUNDED_ENTERED_DR, UNROUNDED_ENTERED_CR, UNROUNDED_ACCOUNTED_CR, and UNROUNDED_ACCOUNTED_DR. XLA_DISTRIBUTION_LINKS also determines whether supplicate subledger journal lines are merged and whether the accounted amounts are calculated by the SLA or passed through.