tpcDriftVelocity drift velocity table in the offline DB have the

following fields:  laserDriftVelocityEast, laserDriftVelocityWest,  cathodeDriftVelocityEast,  cathodeDriftVelocityWest.

As one can see below laserDriftVelocityEast is always eqial to laserDriftVelocityWest (arithmetic average of measured velocities in the East and West).

There is no non zero values for the cathodeDriftVelocityEast and cathodeDriftVelocityWest in the last 5-6 years.

Why don't we write separate values for East/West drift velocities to the DB? Their errors can be stored as well in cathodeDriftVelocityEast and cathodeDriftVelocityWest fileds. Average velocity can be always calucated sowhere in the code. 

mysql> SELECT beginTime, laserDriftVelocityWest FROM tpcDriftVelocity WHERE (beginTime > '2010-01-01 00:00:00' AND beginTime < '2010-01-01 23:59:59' and deactive = 0 ) ORDER by beginTime;
+---------------------+------------------------+
| beginTime           | laserDriftVelocityWest |
+---------------------+------------------------+
| 2010-01-01 05:26:39 |             5.53665018 |
| 2010-01-01 07:06:10 |             5.53533983 |
| 2010-01-01 09:34:32 |             5.53447008 |
| 2010-01-01 10:48:10 |             5.53415012 |
| 2010-01-01 14:01:49 |             5.53392982 |
+---------------------+------------------------+
5 rows in set (0.02 sec)

mysql> SELECT beginTime, laserDriftVelocityEast FROM tpcDriftVelocity WHERE (beginTime > '2010-01-01 00:00:00' AND beginTime < '2010-01-01 23:59:59' and deactive = 0 ) ORDER by beginTime;
+---------------------+------------------------+
| beginTime           | laserDriftVelocityEast |
+---------------------+------------------------+
| 2010-01-01 05:26:39 |             5.53665018 |
| 2010-01-01 07:06:10 |             5.53533983 |
| 2010-01-01 09:34:32 |             5.53447008 |
| 2010-01-01 10:48:10 |             5.53415012 |
| 2010-01-01 14:01:49 |             5.53392982 |
+---------------------+------------------------+
5 rows in set (0.01 sec)