Problem with log data

I logged in an annex to the success of testicular function, including a Time Stamps. As the distance of two records with information
on the cycle time of the plant output, I would like to identify. incl. standard deviation, etc.

I want every record of his predecessor (if possible) identified and the difference in time from the time stamps, and on the basis of this, build a report. The timestamp is unique, ie. so it should go, but I do not know how? The database is PostgreSQL.

Give the table sorted by date, and iterate with a script about it. This is the most elegant way, for all the difference to identify.

Does not contain SQL procedural-imperative constructs. No, for other than PostgreSQL DBMS not. No, not at times Orrible. Therefore, most DBMS procedural extensions (PL / SQL at Orrible, PL / PgSQL to PostgreSQL, MS TransactSQL SQL Server, etc.).