Ledger Parser
Bookkeeping is an essential routine in software computing. A ledger facilitates book-keeping between components. The ledger may have entries that are written by one component and read by another. The syntax and semantics of the writes need to be the same for the reads. However, the writer and the reader may have very different loads and capabilities. Consequently, some short-hand may sneak into the writing and some parsing may be required on the reading side.
When the writer is busy, it takes extra effort to massage the data with calculations to come up with concise and informative entries. This is evident in the cases when the writes are part of online activities that the business depend on. On the other hand, it is easier for the reader to take the chores of translations and routines that are expensive because the reads are usually for analysis which do not have to impact online transactions.
This makes the ledger more like a table with different attributes so that all kinds of entries can be written. The writer merely captures the relevant entries without performing any calculations. The readers can use the same table and perform selection or rows or projection of columns to suit their needs. The table sometimes ends up as being very generic and expands its columns.
The problem is that if the writers don’t do any validations or tidying, the ledger becomes bloated and dirty. On the other hand, the readers may find it more and more onerous to look back a few records because there is more range to cover. This most often manifests as delays and lags between when an entry was recorded and when it made into the reports.
Checks and balances need to be performed as well by some readers. The entries may become spurious and there are ways a ghost entry can be made. Therefore, there is some trade-off in deciding whether the readers or the writers or both do the cleanup work.
The trouble with cleanup is that it requires modifications to the ledger and while they can be done independently by designated agents, they don’t give as much confidence as when they came from the source of the truth as the online writer. Since cleanup is a read-write task, it involves some form of writer.
If all the writes were uniform and clean entries, it does away with the need for designated agents and their lags and delays. At this end of the writer only solution, we have traded-off performance. At the other end of high-performance online writing, we are introducing all kinds of background processors, stages and cascading complexity in analysis.
The savvy online writer may choose to use partitioned ledgers for clean and accurate differentiated entries or quick translations to uniform-entries by piggy-backing the information on the transactions where it can keep a trace of entries