SQL/MX Glossary

Glossary
HP NonStop SQL/MX Glossary—523732-002
Glossary-11
entry-sequenced table
Records can be added or updated but not deleted, but variable-length values cannot
be shortened or lengthened. Entry-sequenced files can be used only with SQL/MP.
Contrast with key-sequenced file.
entry-sequenced table. A table stored in an entry-sequenced file and whose primary key is
a system-generated record address. Entry-sequenced tables can be used only with
SQL/MP tables. Contrast with key-sequenced table.
environment variable. A variable that determines the characteristics of an operating
system environment for a given user. A user or program can set or change
environment variables. Commands or shell scripts evaluate environment variables by
substituting the name of the variable with its assigned value.
ESP. Executor server process. A process that executes a portion of a parallel execution
plan.
ESP parallelism. Any parallel plan with at least one ESP plan fragment. ESP parallelism
occurs when a plan fragment executes within a special process called the executor
server process (ESP).
exact numeric data type. A numeric data type that has both precision and scale. The
precision is a positive integer that represents the number of significant decimal digits.
The scale is a nonnegative integer. The SQL exact numeric types are DECIMAL,
INTEGER, LARGEINT, NUMERIC, and SMALLINT. Contrast with approximate numeric
data type.
exception condition. An abnormal or unexpected result of a programmatic operation.
exchange node. Identifies process boundaries for ESP parallelism and DAM parallelism.
exclusive access. See repeatable read access or serializable access.
exclusive lock. A lock exclusion mode in which only the holder of the lock can access the
locked data, except with read uncommitted access. Contrast with shared lock
.
executable. A prepared application, linked and ready to be loaded from an OSS shell
prompt, TACL prompt, or a translated Java class
, ready to be interpreted by a Java
Virtual Machine (JVM).
executable and linking format (ELF). A standard format used for POSIX object files.
TNS/R native object files are in ELF format with HP extensions.
execution characteristics. The characteristics of an SQL statement’s execution plan that
have no effect on the statement’s semantics. Examples include a plan’s performance,
node autonomy, resource use, and locking strategy.
execution context. A Java object that provides some control over the execution of an
embedded SQL statement (or SQLJ clause) in a Java program and allows the retrieval