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Glossary of Sybase ASE terms
 

A

Allocation:

Allocation Page:  The first page of every allocation unit is an allocation page.  The allocation page contains 32 extent records which indicate which object id, if any, has the extent allocated and which of the 8 pages on that extent are currently in use.  The first extent on the allocation unit is called a "short extent" because the allocation page uses one of the 8 pages, leaving only 7 to be allocated to another object.

Allocation Unit:  Blocks of 256 contiguous pages, starting with logical page 0.  An Allocation unit  is subdivided into 32 8-page #extents, each of which can be allocated to different objects.  The first page of each allocation unit contains the Allocation Page which holds the Extent Records that store information about which object the extents are allocated to.  As a result, the first extent on each allocation unit is called the "short extent" because it has only 7 pages that can store table data and cannot be used by #large scale allocation (LSA).

Anchor:

APL:

 B

B1 Server:

Big Endian:  See #Endian

bigint:

bigdatetime:

buildmaster:  (obsolete).  A utility application that was used to create a new master device.  The buildmaster functionality has been moved into the dataserver binary.

C

Checkpoint:  An event triggered by the system checkpoint process or by a user issuing the checkpoint command.  A checkpoint writes all dirty pages in the database to disk, starting with the log pages. 

CMCC:  Related to the Cluster Cache Coherency Manager.  This is what maintains coherency of pages in memory in the shared disk cluster. In a SMP server there is only one copy of a page in memory. However in a shared disk cluster there can be multiple copies of the page (At most one in each node).  Updates need to be propagated to all copies of the page efficiently.

CR:  Change Request (number).  Generally either a defect (bug) or feature enhancement request.

ct: Often used as shorthand for "client" by support.

 ct-library

D

d_master:  Prior to ASE 11.0, the sysdevices table in the master database did not hold the physical name for the master device.  Instead, the field contained the placeholder "d_master".  The actual master device used by the server is determined by the -d parameter passed to the dataserver binary.

DAM:

DBCC:

dbinfo: A data structure stored on disk containing persistant information about a database, used during recovery to populate the dbtable memory structure. Can be examined using DBCC dbinfo.

db-library

dbtable: A memory structure containing information about an open database. The number of these structures is controlled with sp_configure "open databases". The current and high-water usage is reported by sp_monitorconfig. Can be examined using DBCC dbtable

definition-time object: Definition time objects are created by ASE in the process of generating a query tree.  They are temporary placeholders for objects that will be created in the batch by SELECT INTO or CREATE statements.  Definition time objects are normally dropped after query plan generation (compilation) but before execution.  ASE Error 12336 can occur if the process that created the definition time object was terminated before it dropped the object.

DES:   A memory structure (object descriptor)  that holds information about a particular object in the database. 

Disjoint: In showplan output, this indicates a lack of a join clause, resulting in a cartesian product.

DOL: Data-Only Lock scheme.  General term for datapages and datarows lock schemes.  Transactional locks are only held on data pages, shorter duration latches are used on index pages.

E

EBF:
Endian: refers to the ordering of bytes in multi-byte datatypes being from most significant to least significant (big-endian) or the opposite (little-endian). There is a good writeup on Wikipedia. Big-endian representations of unsigned integer values are the same as typcial human-readable hexidecimal values: select convert(binary(4), convert(int,1)) will return 0x00000001 on a big-endian system and 0x01000000 on a little-endian system.

 EOL:  End of Life.  Generally refers to the date that a product stops being supported in terms of engineering providing fixes in compiled binaries for the product.

Equivalence Mapping:  Some character sets (notably Asian) have versions of characters that look like ASCII characters A-Z, a-z and punctuation. Equivalence Mapping treats these characters as their ASCII equivalents for purpose of SQL language keywords and punctuation recognition.

 ER: Engineering Request. 

 ESD: 

Extent:

 F

FRID: Fixed Row Identifier.  Rows in tables using the DOL lock scheme have fixed row ids.  The row id for the page is guaranteed not to change while a transaction is in progress.  In general, REORG REBUILD is the only command that changes DOL row ids

Fragmentation:

G

GAM: see Global Allocation Map

Ghost Process:  see #Phantom Process

Global Variable: General name for predefined variables in ASE that have names staring with two asterisks, such as @@version.  Some of these are truly global, giving the same value to all sessions, while others are actually session-specific.  See also Variables.
Global Allocation Map:

 H

HA: High Availability. ASE feature that provides failover to another host that can access the same set of hard drivces in the event of host failure (cpu, memory) other than the disk system

HF: Hot Fix.  A rollup containing a number of more important bug fixes that is released between scheduled PL releases due to the urgent nature of the fixes.

HK: Housekeeper 

 I

Identity:

INF:  A floating point datatype value, stands for "infinity".  

installcommit:  The name of the script that creates the contents of sybsystemdb.

installmaster:  The name of the script that creates the standard set of system stored procedures.  Most of these procedures are created in the sybsystemprocs database; the name of the script predates the introduction of sybsystemprocs, before which the system procedures were all created in the master database.

Instead-Of Trigger: A type of trigger that can be created on a view.  The trigger code is executed when a user attempts to insert, update, or delete data in the view. 

IO Fencing:

Isolation Level: See Transaction Isolation Level

 L

Large Scale Allocation:

Little-endian:  See #Endian

LOB:

Log Transfer Manager

LSA see Large Scale Allocation.

LTM see Log Transfer Manager

LTM Marker: A pointer, held in the dbinfo structure, pointing to the most recent page in the syslogs table that has been processed by replication.

M

Maintenance Token:  The "maintenance token" value shows up under the command field in sp_who output.  ASE stores all the command names in an array, "Maintenance Token" is the first entry in the array, and usually indicates that the spid is still being initialized and hasn't yet executed any statement.

MDA:

N

n-off:   See One-Off. 

NaN:  A floating point datatype value, stands for "Not A Number".   NaN values are valid floating point values in general, but aren't allowed under the ANSI SQL standards. 

navigator_role:  A system role that is obsolete and not used for anything in ASE, though it still shows up in the syssrvroles table.  Navigator_role was used for a circa 1995 parallel shared-nothing offshoot of ASE called Navigation Server.  See http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=380394&tag=1

O

 One-Off (also 1-off):  A release (patch) based on a rollup release that has one additional bug fix added.   Releases with more than one fix added may still be called one-offs but are sometimes named for the number of fixes added, i.e. two-off, three-off, ..., seven-off, etc. or may be more generally called an n-off. 

 P

Page Header:  Every page in an ASE database starts with a 32-byte page header that includes information such as the page number, the object id the page is allocated to, the timestamp of the most recent change to the page.   Example


 
Parse Tree:

Phantom Process
:  A process, usually a user connection, that no longer exists in sysprocesses but is still holding locks in syslocks.  Sometimes called Phantom Locks, but the locks are very real, it is the process that is a ghost.  Compare with Zombie Process.

Phantom Lock:  See Phantom Process.

PL: Patch Level.  A collection of primarily bug fixes with possibly a few new feature enhancements, theoretically released on a planned schedule between SP releases.

Q

Quickpass  Component Integration Services (CIS) processing mode that passes entire query to a remote server for processing.

 R

Release, Minor:

Release, Major:

RID:  Row Identifier.   See also FRID.

Role: Roles are collections of privileges that allow the role assignee to perform their job. The roles supported by Adaptive Server let you enforce individual accountability. Adaptive Server provides system roles, such as system administrator and system security officer, and user-defined roles, which are created and granted to users, login profiles, or other roles by a system security officer. Object owners can grant database access as appropriate to a role. 

Rollup:

RVM:  (Reference Validation Mechanism)

S

SDES:  A memory structure (scan descriptor) that keeps track of a querie's current place when scanning a table or index.

Service Pack:  SAP-style nomenclature for EBF releases previously known as ESDs.  New features are usually introduced in SP releases as opposed to PL releases.

SBSSAV:  "SAP Business Suite Specific ASE Version".  From @@sbssav, a global variable introduced in 15.7 GA to provide a simple version string as an easier method of determing the ASE version than parsing @@version or using sp_versioncrack.

SEGV:  SEGment Violation.  Another term used for an INFECTED WITH 11 error.

Short Extent:  The first extent of each allocation unit.  The first page of the first extent is used up storing the contents of the Allocation Page, leaving only 7 pages that can be used to store data for the table the short extent is allocated to.  Short extents cannot be allocated by processes using Large Scale Allocation (LSA).

SP:  see  Service Pack (a release version identifier), Stored Procedure, or System Procedure

ST-Node:

Stored Procedure:

Suffix Compression:  A feature used to reduce the size of index trees.  On non-leaf levels of DOL indexes, the page contains only as much of the key as is needed to distinguish between two branches, the rest of the key value (the suffix) is truncated.

sysgams:  A system "table" that contains the #Global Allocation Map (GAM) datastructure.  Although it appears to be a table in many ways, the contents cannot be directly viewed with SELECT.  DBCC GAM can be used to check the consistency of the GAM's data and correct any errors.

System Procedure:  A stored procedure provided with ASE.  Most system stored procedures are stored in the sybsystemprocs database (a few are stored in the master database) and have a name that starts with 'sp_'.   When a stored procedure starting with 'sp_' is executed, ASE first looks for a procedure  by that name owned by the user in the current database, then for one owned by dbo in the current database, then for one owned by dbo in sybsystemprocs, then for one owned by dbo in the master database.

Suicide (the log):

T

TDS (Tabular Data Stream):  The protocol used to communicate between client applications and ASE.  For more information, see the TDS 5.0 Technical Specification document .

Textpointer:  When a table contains text or image (LOB) columns that are stored off-row, a 16-byte varbinary value called a textpointer is stored in the row for each value instance.  The first 4 bytes of the text pointer contain the page number of the first page of the LOB value.  The textpointer value can be retrieved using the txtptr() function.

Timestamp:  An ASE datatype that is a 6-byte binary counter that automatically increments with each update.

TIPSA (Text Image Process Status Area):  A datastructure stored on the first page of each text value that contains metadata about the text value.

Transaction Isolation Level:  see product manuals

U

V

Variables:   local (with one @ sign), session and global (with two @ signs), and parameterized sql (with three @ signs)

W

Write-Ahead Log:

X

xpserver:

XPDL:  Cross Platform Dump and Load


 Z

Zombie Process:  A process that is running but won't die when the KILL command is used against it.  Compare with Phantom Process.

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