> I would be interested in a "gstat -r -i <yourdatabase>" output before
> and after the update statement.

Database header page information:
Flags 0
Checksum 12345
Generation 24711032
Page size 8192
ODS version 11.2
Oldest transaction 24703155
Oldest active 24703156
Oldest snapshot 24703156
Next transaction 24703162
Bumped transaction 1
Sequence number 0
Next attachment ID 7869
Implementation ID 26
Shadow count 0
Page buffers 0
Next header page 0
Database dialect 3
Creation date Feb 17, 2012 6:37:00
Attributes force write

Variable header data:
*END*

Analyzing database pages ...

TMPD (129)
Primary pointer page: 155, Index root page: 156
Average record length: 35.94, total records: 5733324
Average version length: 13.02, total versions: 120050, max versions: 11
Data pages: 283259, data page slots: 294185, average fill: 42%
Fill distribution:
0 - 19% = 98046
20 - 39% = 62050
40 - 59% = 36012
60 - 79% = 30869
80 - 99% = 56282

Index RDB$PRIMARY2 (0)
Depth: 3, leaf buckets: 32987, nodes: 5735058
Average data length: 17.87, total dup: 0, max dup: 0
Fill distribution:
0 - 19% = 104
20 - 39% = 3259
40 - 59% = 21604
60 - 79% = 8003
80 - 99% = 17

SESSION (128)
Primary pointer page: 151, Index root page: 152
Average record length: 132.46, total records: 4776414
Average version length: 163.22, total versions: 1144937, max versions: 112
Data pages: 125031, data page slots: 288637, average fill: 90%
Fill distribution:
0 - 19% = 13
20 - 39% = 1
40 - 59% = 0
60 - 79% = 0
80 - 99% = 125017

Index RDB$PRIMARY1 (0)
Depth: 3, leaf buckets: 31883, nodes: 4784198
Average data length: 13.89, total dup: 0, max dup: 0
Fill distribution:
0 - 19% = 32
20 - 39% = 22154
40 - 59% = 7753
60 - 79% = 1369
80 - 99% = 575

is that look bad or good ?