Technical Overview, mem peak info table

The mem_peak_info table in the peakdb database is used to generate the MRM displays for protein and peptide information in GPMDB.

The main difference between this table and the other tables that make up the GPM is that it is a memory table; the contents of this table reside in the database server's memory, to increase the response time for queries involving these tables.

The contents of this table are updated manually, when new source data files are generated.

Columns:

• id: the unique identifier for this set of peaks. This id column corresponds to the peptide with the same id value in the mem_peptides table, so these two tables will always have the same number of rows.
• mass_(x): the mass of the x-th peak.
• peak_(x): the peak associated with the x-th mass.

Note: there are twenty mass_(x)-peak_(x) pairs in the mem_peak_info table numbered 1 to 20 inclusive, for a total of 41 columns. Not all columns are filled with data in all rows, but they are filled starting with the first. The first column with a zero value stored for the mass implies that the remaining columns are all zero, meaning there is no more data stored for this peptide.