Sybase ASE consists of
1.Processes (Dataserver/Backupserver)
2.Executable files
3.Internal threads
4.System databases
5.Shared memory
1.There 2 process for ASE one is Backupserver
and another one is data server. ASE backup server which will help in supporting
the dump and load of database and transaction log. Dataserver will help to
maintain all other ASE operations.
2.ASE executable files are RUN server file,
contains certain parameters that are required to startup the dataserver(ASE)
also it contains the path/ location of error log file(which logs all
console/error messages), location of configuration file(helps us in giving the
information of the configuration parameters that are currently being set for
the functionality of ASE), location of interface file(gives us information
related to the connectivity), logical page size of the server.
3.ASE internal threads 'port manager, network
handler, ASTC handlers, HK chores, HK wash, HK GC, checkpoint worker,
checkpoint sleep, mirror handler, deadlock tune, license heartbeat'.
4.When ASE is installed by default master,
model, sybsystem, tempdb and sybsystemprocs will be created, we can create user
databases and some additional databases called sybmgmtdb, sybsecurity, dbcc
db.
5.Coming to shared memory, it is divided into three
parts
Procedure cache: SAP ASE maintains
an MRU/LRU (most recently used/least recently used) chain of stored procedure
query plans.
As users execute stored procedures, SAP ASE looks in the procedure cache
for a query plan to use. If a query plan is available, it is placed on the MRU
end of the chain, and execution begins.
If no plan is in memory, or if all copies are in use, the query tree for
the procedure is read from the sysprocedures table
this will contain another component called 'statement
cache' which holds the recently executed SQL query/ abstract plan.
The statement cache is a server-wide resource,
which allocates and consumes memory from the procedure cache memory pool.
https://help.sap.com/docs/SAP_ASE/91d32d977a174c68829880bc020fc352/a99c032fbc2b10148ea4c5dc158b54e7.html
Data cache: This contains
the recently executed data. By holding the data in this cache i/o will be
reduced thereby increasing the performance. If the data is being fetched from
the disk, it is known as 'physical i/o' and if the data is being fetched from
the cache it is known as 'logical i/o'.
Log cache: This will hold the logs that are being generated with
respect to any DML statements happened on the data.
