发信人: Modeler ((Balance)), 信区: Database
标 题: Fragmented databases behind Scottish election debacle(ZZ)
发信站: BBS 未名空间站 (Tue May 15 18:25:49 2007)
Fragmented databases behind Scottish election debacle
Bad paper led to bad data led to general mayhem
Tash Shifrin May 11, 2007 (Computerworld UK) -- The sheer volume of
spoiled ballot papers in the Scottish elections last week led to technical
problems with electronic counting systems that delayed the results and
caused angry debate in both the Scottish Parliament and House of Commons,
according to the technology provider.
Supplier DRS, which attributed the delays in five areas to data
consolidation problems and "fragmentation" of databases, has given
Computerworld UK a more detailed explanation of the problems it encountered,
though its internal inquiry continues.
The DRS e-counting machines are designed to read and recognize both the X
marks used by voters in the Scottish Parliament elections and the hand-
printed numbers used on the transferable voting ballot papers for the local
In the immediate aftermath of the elections, DRS said the scanners used to
read each vote -- or capture an image of unclear ballot papers for
adjudication by the returning officer -- had worked without problems.
But a spokesperson added, "The issue involved a blockage at the end of the
counting process, which prevented consolidation of the data." This meant the
results could not be announced.
The company has now offered a more detailed explanation of the glitch. A
spokesperson said, "The DRS e-counting systems encountered significant
fragmentation (up to 99%) of a number of the database indexes, which caused
the complex queries required to produce final results and some status
summary reports to time out.
"Whilst investigations are still under way to understand the precise reason
for the index fragmentation, at this early stage it remains likely that the
number of rejected ballots was the major contributory factor."
The level of rejected -- or "spoiled" -- ballot papers had been far higher
than expected, with figures obtained by the BBC from returning officers at
each counts showing a total of nearly 142,000 rejected papers -- almost 7%
of the votes cast.
The DRS spokesperson said, "The database had been tuned for the expected
levels of workflow which had not included the unforeseeably high level of
ballots that ultimately had to be rejected."
She added, "DRS is a Microsoft Certified Partner and the e-Counting system
was designed around the latest Microsoft SQL 2005 Server technology. Over
the past 18 months, DRS has been thoroughly testing the system using a team
of ISEB quality engineers.
"Numerous load tests were conducted to 135 percent of maximum predicted
capacity and at no time during these tests was index fragmentation an issue."
Returning officers at five affected sites decided to adjourn the election
counts for several hours to allow a fix to be thoroughly tested before
proceeding. The problem was eventually remedied by index defragmentation,
which restored all five systems to full working order.
DRS said it deeply regretted the delays and the frustrations experienced by
returning officers, staff and candidates.
The company's technology was also used for electronic counting of the London
Assembly elections in 2000 and 2004 without any problems.
The Scottish election delays are to be investigated by the Electoral
Commission. The inquiry will also look at problems with the elections
unrelated to the technology, including the high number of rejected ballots.
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