On Mon, Nov 11, 2013 at 07:25:59PM -0800, David Johnston wrote: > This reads badly to my ears: > > > > This means that while querying a database each SQL statement sees a > > snapshot of data (a database version) as it was some time ago, regardless > > of the current state of the underlying data. > > How about something closer to: > > > > This means for each SQL statement the user can specify a relative > > point-in-time snapshot (database version) of the database against which to > > query. These snapshot options are 1) the most recent committed data > > currently available database-wide - including implicit commits (see note), > > or 2) the committed data as-of the beginning of the current transaction - > > including any changes made in the same. > > > > Note: an implicit commit occurs only within a multi-statement transaction. > > For the purpose of determining if data has been committed any prior > > statements in the same transaction are deemed to have been committed when > > viewed by later statements. > > I know this is an introduction paragraph so the broad concept is being > focused on rather than how such a user would in fact make this choice. > > I don't know that the term "implicit commit" is used elsewhere, likely not, > but in effect that is what a statement in a transaction is seeing with > respect to prior statements in the same transaction. Naming this behavior > in the introduction would allow for someone less verbose descriptions to be > used in detail sections. > > The above could be better integrated into the intro but I wanted to get > opinions on the approach first.
We just want to get across the MVCC concept in the intro --- we cover the snapshots later in the document. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-docs mailing list (pgsql-docs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-docs
