Sybase ADAPTIVE SERVER IQ 12.4.0 User Manual

Page 25

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Adaptive Server IQ 12.4.0

Recommended index types

Release Bulletin for Digital UNIX 25

9.2.12 Recommended index types

In the Adaptive Server IQ Administration and Performance Guide, Chapter 4,
“Adaptive Server IQ Indexes,” in Table 1–2, Query type/index, the
recommended index types for

COUNT

and range predicate are incorrect. The

correct types are:

Note

While

HNG

is recommended, in certain cases

LF

or

HG

is faster, and is

often used in place of

HNG

.

HNG

tends to give consistent performance, while

the performance of

LF

or

HG

with ranges depends on the size of the range

selected.

9.2.13 Changes to “Using join indexes”

The section “Using join indexes” in the Adaptive Server IQ Administration and
Performance Guide
, Chapter 4, “Adaptive Server IQ Indexes, has several
errors, described below.

Privileges needed to create a join index

The book states that you must be the owner of a table or the DBA to create,
alter, or synchronize a join index that includes that table.

If you are not the DBA, you need to be owner of the table and have
RESOURCE authority
in order to create a join index.

One-to-many relationship

The following changes apply to the subsection “One-to-many relationship.”

The first sentence of the third paragraph should read, “If the join column is
made up of more than one column, the combination of the values must be
unique on the “one” side.

The example described in the third and fourth paragraphs is changed to match
the asiqdemo database, and include sample rows that were omitted. The
warning that follows these paragraphs is also changed. The corrected
paragraphs read as follows:

Type of Query Usage

Recommended Index Type

As

COUNT

argument

LF or HG

In range predicate in

WHERE

clause (>,

<, >=, <=,

BETWEEN

LF or HNG

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