 | Level: Intermediate Mark Baldridge , Principal Consultant, North American Lab Services, IBM
13 Nov 2008 In this installment of the
UniVerse performance series,
explore the cost of opening files in BASIC programs. Measure opening simple
hash files, dynamic files, and directory files, and measure the impact of
adding indices to files. Time open distributed files, with and without
indices, and examine variations by looking at
OPENSEQ and OPENPATH.
Objectives
Contrast the expense of opening files in different configurations, in preparation for exploring ways to avoid them.
Prerequisites
You should have a familiarity with writing and
compiling UniVerse BASIC programs.
System requirements
This tutorial requires an installation of UniVerse. You can
download
a Personal Edition of UniVerse for Linux or Windows.
Duration
Less than two hours
Formats html, pdf
Tutorial overview
This
series
of tutorials provides UniVerse DBAs and application designers with
tools for making reasoned and metrically-justified decisions about
choices in everyday tasks. The subject matter of this series on
UniVerse performance tuning arises from visits to customer sites. The
issues raised do not disparage the customer, but reflect a real-world
predicament. The typical developer or DBA has so many outstanding
tasks that by the time one task is complete, at least one more has
joined those remaining. They all demand attention. Sufficient time
exists to make something work, but typically not enough to make it
work well.
With this installment, explore the cost of opening files. Measure
opening simple hash files, dynamic files, and directory files, and
measure the impact of adding indices to files. Time open distributed
files, with and without indices, and examine variations by looking at
OPENSEQ and
OPENPATH.
| | | |
