Hi,

Im facing a problem where I need to query time series information from
a table stored in a FB 2.1 datbase.

The problem is that I need to query one record before and after the
actual period specified in the select statement.

Example table:

Time Data

1 X
2 X
3 X
4 X
5 X


select Data from XY where time>= 2 and time<=4

Here I need record with time 1 and 5 also.

Easy you might think, but the problem is that the timeserie is not
uniform, the table might look like this:


Time Data

1 X
5000 X
5100 X
5200 X
5400 X
5700 X
9000 X

select Data from XY where time>= 5000 and time<=5700

Here I also need record with timestamp 1 and 9000.

Any suggestions how to solve the problem is very welcome.