E110 Best Practices for Implementing with Adaptive Server IQ

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E110Best Practices for Implementing with
Adaptive Server IQ

• Mark Mumy
• Principal Systems Consultant
• Business Intelligence Division
• mark.mumy_at_sybase.com

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About This Presentation

• Hardware Configuration
• Creating the Database
• IQ-M Server Settings
• Connectivity
• Data Model Recommendations
• Database Programming
• Data Manipulation
• Maintenance Tasks
• Memory Usage

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Target Audience

• Database Administrators
• All Levels
• Query Developers
• All Levels

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For This Presentation

• Lets Keep It Interactive
• I will entertain questions on a subject
• Would be happy to speak to you offline, if
  desired
• No Question is too Basic
• Chances are others may have the same question
• Open Question Forum at the end
• Time Permitting

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Hardware Configuration Drive Arrays

• Volume Manager
• Not a necessary or recommended component for IQ-M
• Additional overhead and software that has no
  value add to an IQ-M installation
• Acceptable for an IQ-M single node operation
  where hardware does not have the ability to apply
  RAID to the disk devices
• RAID Level
• Recommend using RAID 5 as a blend between
  performance, protection, and cost
• Recommend using raw devices (a must for
  multi-node IQ-M)
• For details on drive array specifications and
  configurations see the Sun Reference Architecture
  Whitepapers and EMC Whitepapers on array
  configurations with IQ-M

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Hardware Configuration Memory

• How Much RAM for IQ-M
• As much as possible!
• Most systems should have at least 2 GB
• Dont forget additional RAM for each load being
  performed

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Hardware Configuration Processors and Disk
Controllers

• Optimal CPU configuration
• Queries 1 CPU per active query more if queries
  are complex and can be run in parallel
• Loads 1 CPU per HG index plus 1 CPU per 2-5
  columns being loaded
• Disk Controllers
• 1 fiber controller per 5 write CPUs
• 1 fiber controller per 10 read CPUs
• In mixed mode operation use the 51 ratio
• Recommend a minimum of 2 controllers

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Creating The Database Creation Options

• Creation Options
• Block Size and Page Size
• Minimum should be 128K Page Size (8K Page)
• Use 256K Page for larger databases
• Larger the page size the more RAM that will be
  required
• CASE IGNORE vs. CASE RESPECT
• Use CASE RESPECT whenever possible
• Removes case comparison steps and improves
  performance
• Java in the Database
• Install if Java will be needed in the database
• No impact if installed and not used

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Creating The Database File Placement

• Use relative links makes it easier to relocate
  files
• Use symbolic links for IQ MAIN and IQ TEMP
• /IQM_devs/IQ_MAIN_00
• /IQM_devs/IQ_TEMP_00
• Place the transaction log and transaction log
  mirror on significantly large file system
• Recommend 5 GB of filesystem space per IQ-M node
  for database related storage
• Transaction logs, IQ MSG, scripts, catalog file,
  etc

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Creating The Database Files Locations

• Filename rules
• Keep the names unique for each IQ-M node
• Catalog DATABASE_NAME.db
• Transaction log DATABASE_NAME.tlog
• IQ MSG DATABASE_NAME.iqmsg
• IQ Main Store DATABASE_NAME_iqmain_000
• 000 would be an incrementing number
• IQ Temp Store DATABASE_NAME_iqtmp_000
• 000 would be an incrementing number
• IQ Configuration File DATABASE_NAME.cfg

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IQ-M Server Settings Query Performance

• FORCE_NO_SCROLL_CURSORS
• Should always be set to ON
• Very few applications require this to be OFF
• Can improve query performance

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IQ-M Server Settings Query Plans

• Query Plan Settings to Provide Optimal Query
  Information to DBAs and Sybase Engineering
• set temporary option query_plan'on'
• set temporary option query_plan_after_run'on'
• set temporary option query_timing'on'
• set temporary option query_detail'on'
• set temporary option dml_options10'on'
• set temporary option query_plan_as_html'on'
• set option QUERY_NAME Query Name
• Should not be set globally as the IQ MSG file
  will grow rapidly

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IQ-M Server Settings Storage

• Append_Load
• Can be used to improve load performance
• Will not reuse Row IDs or the space occupied by
  those Row IDs
• Great for systems where large, contiguous chunks
  of data are deleted
• May not good if random rows are deleted as it can
  lead to fragmentation and allocated, but unused
  space

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IQ-M Server Settings Storage Continued

• Disk_Striping
• If ON, IQ-M will stripe writes to all available
  devices
• If OFF, the first device must be full before the
  next is used
• Disk_Striping_Packed
• If ON, it forces better space usage and less
  fragmentation
• Fragmentation is indicated when out of space
  messages are returned but the main dbspace used
  is less than 100 full
• Allows Adaptive Server IQ to better utilize small
  pieces of unused space that remain after
  compression

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IQ-M Server Settings Data Loads

• LOAD_MEMORY_MB
• Set to 0 (default) on systems with enough RAM
• Set to something lt 500 on systems where RAM is
  tight or there are simultaneous loads taking
  place

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Client Access and Network Connectivity

• Different internal environments and settings for
  ODBC, JDBC, and Open Client connections
• JDBC and ODBC are recommended
• JConnect is Sybases implementation of JDBC
• Use the JDBC 2 driver (JConnect 5.2/5.5)
• com.sybase.jdbc2.jdbc.SybDriver
• Open Client
• Use with caution
• Most applications written using Open Client
  expect an ASE server

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Client Access and Network Connectivity Open
Client vs. ODBC

• See Chapter 32 of the ASA Users Manual as well as
  the ASA Reference Section Transact-SQL and
  SQL/92 compatibility options for complete list
  of differences
• If writing stored procedures or embedded
  application code, make sure to explicitly make
  settings for compatibility as these options will
  get set to different values for Open Client vs.
  ODBC connections
• ALLOW_NULLS_BY_DEFAULT
• QUOTED_IDENTIFIER
• STRING_RTRUNCATION
• ANSI_BLANKS
• ANSINULL
• CHAINDED

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Client Access and Network Connectivity

• AutoPreCommit Within ODBC
• Set registry setting AutoPreCommit to Y
• Forces applications to issue a COMMIT before each
  query
• Go to the registry and update the corresponding
  Sybase Data Source Name (DSN) created, by adding
  a new value 'AutoPreCommit with a value of Y'
• HKEY_LOCAL_MACHINE/SOFTWARE/ODBC/ODBC.INI/DSN
• Packet Sizes
• Larger packet sizes will help with large data
  retrieval
• Use p option in IQ-M configuration file to
  increase size
• Use CommBufferSize parameter in ODBC connection
  string

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Client Access and Network Connectivity

• Network Speed
• Data retrieval will be as fast as the network
• 100 MB of data will take 80 seconds on a 10 Mbit
  LAN
• 100 MB of data will take 8 seconds on a 100 Mbit
  LAN
• 100 MB of data will take 0.8 seconds on a Gigabit
  LAN
• LAN speed may be the performance bottleneck for
  queries that return large amounts of data
• The faster the network cards and LAN the better
  off concurrency will be more available bandwidth
  per user
• Network Interface Cards
• Adding multiple network cards to the IQ-M node
  will help with network

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Client Access and Network Connectivity

• ASE Component Integration Services (CIS)
• Can have ASE CIS reference IQ-M tables (proxy
  tables)
• Use ASE 12.5 CIS class of ASIQ
• Prior to to ASE 12.5 ASAnywhere or ASEnterprise
  classes had to be used
• Not a viable option if joining non-IQ-M tables
  with an IQ-M proxy table
• Can map multiple ASE logins to a single IQ-M
  login
• Data modifications should not be performed on
  proxy tables
• Can map ASE proxy tables to stored procedure
  calls in IQ-M

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Client Access and Network Connectivity

• IQ-M Component Integration Services (CIS)
• Can only be used on the Solaris and WinNT
  versions of IQ-M
• Can map to tables in Oracle (ODBC), ASE (ODBC
  JDBC), ASA (ODBC JDBC), DB2 (ODBC), MS SQL
  Server (ODBC), and any ODBC source
• Not a viable option if joining IQ-M tables with
  non-IQ-M proxy tables
• Data modifications may be performed on proxy
  tables

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Data Model Recommendations IQ UNIQUE

• Use whenever possible to help save storage space
  and possibly improve query performance
• Not necessary for cardinality greater than 64K
  (65536)
• Not necessary for datatypes of tinyint or char(1)
• Does not need to be exact, but should be close to
  cardinality
• If the value is lt 255 then IQ-M will place a
  1-byte FP index on the column 1 byte of storage
  per row
• If the value is gt 255 but lt 65536 then IQ-M will
  place a 2-byte FP index on the column 2 bytes
  of storage per row
• May slightly hinder data loads, but improve query
  speeds

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Data Model Recommendations NULL Values

• Always specify NULL or NOT NULL
• Open Client and ODBC connections have different
  defaults
• Allows the optimizer a better guess at join
  criteria
• NULL data does not save space on the database
  page as it would in ASE
• Will be compressed out when stored on disk

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Data Model Recommendations Unsigned Datatypes

• Use unsigned datatypes where possible
• Use for surrogate keys and join columns
• Unsigned data comparisons are quicker
• The caveat to this is that Open Client may
  misinterpret the value if it is too large as it
  does not understand large unsigned data
• Can convert to signed integer, numeric, or
  decimal if returning data to an Open Client
  application
• This caveat applies to moving data between IQ-M
  servers with INSERT FROM LOCATION

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Data Model Recommendations Long Varchar and
Long Varbinary

• Can be used to store large amounts of text or
  binary data
• VARCHAR() or VARBINARY() datatypes
• Maximum width is 32K (32768) bytes
• The WORD index is the only index allowed on data
  256 bytes or wider
• Storage will be allocated in 256 byte chunks
• A 257 byte string will require 512 bytes of
  storage
• Much less than the 2K requirement in ASE TEXT and
  IMAGE columns

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Data Model Recommendations Varchar vs. Char

• Use CHAR() whenever possible
• All data in IQ-M is stored fixed width
• VARCHAR() types only add overhead
• A VARCHAR(100) columns will require 101 bytes of
  storage
• 100 bytes for data
• 1 byte for the size of data
• CHAR() data is blank padded, VARCHAR() is not

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Data Model Recommendations Proper Datatype
Sizing

• Use the smallest datatypes possible for data
• Be aware of all datatypes in IQ-M there may be
  more than you know
• If hour, minute and second information is not
  necessary, use DATE instead of DATETIME
• If the data will fit within a TINYINT or SMALLINT
  datatype use that rather than INTEGER or BIGINT
• Allows the engine to store data in smaller units
  (1-byte TINYINT or 2-byte SMALLINT versus 4-byte
  INTEGER or 8-byte BIGINT
• Dont over allocate storage when defining
  NUMERIC() or DECIMAL() as it can be costly for
  data that doesnt need all that space

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Data Model Recommendations When and Where to
Use Indexes

• Always use indexes on
• Join columns
• Searchable columns
• Aggregation columns
• If uncertain, place an LF or HG index on the
  column
• A column with an HNG, CMP, or WD index should
  have a corresponding LF or HG index (very rare
  circumstances will negate this)
• Indexes are not needed on columns whose data is
  ONLY returned to the client (projected)
• Use Primary Key or UNIQUE HG indexes where
  appropriate

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Data Model Recommendations Multi-column Indexes

• Currently, only UNIQUE HG and PRIMARY KEY indexes
  support multiple columns
• HG inserts are the most expensive in IQ-M
• Try to guarantee that inserts will happen at the
  end of the index
• Place generally incrementing data at the
  beginning of the index list
• For instance, a transaction date or batch number
• Something that will try to guarantee a sequential
  key

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Data Model Recommendations Join Column

• Prefer joining integer datatypes (unsigned if
  possible)
• Integer comparisons are quicker than character
  comparisons
• Keep the datatypes as narrow as possible to
  improve join performance

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Data Model Recommendations Primary Keys

• Multi-column primary keys should have an
  additional LF or HG index placed on each
  individual column
• Must be done manually
• UNIQUE CONSTRAINT, UNIQUE HG, and Primary Key are
  identical structures HG index with no G-Array
• Use when possible
• Helps optimizer make more informed query path
  decisions even if index is not used in joins or
  searches
• You get an HG Index created automatically
• This HG index has no G-Array (uses less space)

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Data Model Recommendations Temporary Tables

• 3 Types of Temporary Tables
• tables
• create table temp table ( col1 int )
• Local Temporary Tables
• declare local temporary table temp table ( col1
  int )
• Behave just like tables
• Global Temporary Tables
• create global temporary table temp table ( col1
  int )
• Tables structure is static across connections and
  reboots

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Data Model Recommendations Temporary Tables

• On Commit Preserve Rows
• Use this option so that rows in temporary tables
  remain after the transaction has been committed
• Temporary tables are available at the current
  level (parent) and all of its children
• A parent cannot see a child's temporary table(s)

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Data Model Recommendations Cursors

• Avoid using cursors
• Generally means row based processing
• IQ-M was designed for set based processing
• Sometimes they cannot be avoided
• Open With Hold
• Allows the cursor to remain open across
  transactions
• If not used, the cursor is closed when a commit
  is issued

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Database Programming Language Watcom SQL vs.
T-SQL

• IQ-M (ASA) is not 100 T-SQL Compatible, but very
  close
• Recommend using Watcom SQL
• All system procedures written with it
• Many more code examples and more IQ-M people
  versed in it
• Watcom SQL has some extensions that T-SQL does
  not
• Dynamic SQL
• Better Loop control
• Full cursor movement rather than just read next
• Batches and procedures must be written in the
  same dialect
• Cannot mix T-SQL with Watcom SQL

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Database Programming Language Watcom SQL vs.
T-SQL

• Behavior differences include

• DECLARE CURSOR
• GOTO
• IF
• PRINT
• RAISERROR
• SET

• WHILE (T-SQL) vs. LOOP
• Global variables
• Variable Names
• CALL
• FOR
• ASA requires variables to be declared immediately
  after a BEGIN

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Database Programming Language Commit and
Rollback

• Use transaction control around logical units of
  work, even read only queries
• Should commit before a read/write batch is
  started to ensure latest version of data is
  available
• Should issue commit and rollback after batch
  completion to release all query resources
• Rollback will free memory resources in use by
  previous operations

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Database Programming Language Custom Functions

• Custom functions can be written in either SQL or
  Java
• Great way to encapsulate business logic for
  transforming data
• Can have a significant performance impact on
  queries
• Functions are executed in the catalog portion of
  the engine
• All result rows may need to be moved to ASA
• Can be time consuming for large result sets
• Turn on query plans to see what impact the
  functions have on effective query plans

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Database Programming Language Outer Joins

• T-SQL Outer Join or
• ANSI Standard/Watcom SQL Outer Join
• leftrightfull outer join
• Be careful of outer join syntax
• The T-SQL syntax can be very ambiguous or
  non-deterministic for IQ-M to translate
• All T-SQL outer joins must be converted to ANSI
  outer joins and then processed
• Use the ANSI standard instead as they are not
  ambiguous and are always clear in their meaning
• Visit http//my.sybase.com/detail?id1017447 for
  more details

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Data Manipulation Load Table

• Parallel Load Table
• Make sure to put column delimiter after last
  column
• Must use ROW DELIMITED BY and DELIMITED BY
  options in load table command
• Column and row delimiters must be a single
  character
• 1 to 4 byte delimiters allowed for serial loads

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Data Manipulation Load Table

• If possible, perform load table from binary
  datafiles
• Can be 3 to 10 times faster than ASCII loads
• Can use FILLER() clause with a delimiter or byte
  count
• Better performance achieved by casting the date
  or datetime formats rather than letting IQ-M
  guess
• If possible, issue a single load table with
  multiple files rather than 1 load table per file
  to be loaded into a table

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Data Manipulation Insert From Location

• Great way to move data from any Open Client
  source
• Syntax
• insert into TABLE()
• location SERVERNAME.DBNAME
• select statement
• IQ-M username and login must match on remote
  system
• Interfaces entry must match the SERVERNAME
• Can also be used to move data quickly from an ASA
  table to an IQ-M in the same server

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Data Manipulation Single Row Operations

• Avoid at all costs for large data manipulation
  operations
• Different from single statement operations that
  modify many rows
• Individual INSERT VALUES() will be slower than
  bulk load operations
• Expect no more than 5,000 to 20,000 operations
  per hour

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Data Manipulation Named Pipes and Flat Files

• Named pipes can be faster no disk I/O
• How to make a named pipe
• mknod PIPE_NAME p
• Can use BCP, GZIP, UNCOMPRESS, or applications to
  push IQ-M formatted data into named pipe
• LOAD TABLE command can read from named pipe
• Can also fast extract data to named pipes so that
  they can be read by another application or even
  compressed and stored

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Data Manipulation Partial Width Inserts

• Can induce fragmentation and overly large space
  consumption if not watched
• Row IDs from deleted data are not reused during
  a partial width insert operation
• Space from delete data is not reused (because Row
  IDs are not reused)
• Partial width inserts are analogous to
  APPEND_LOADon in terms of Row ID and space
  behavior
• Only becomes a problem if partial width inserts
  are a way of life for a table

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Data Loading The Deep Fact Table

• Many databases have a deep table
• A growing table with tens of millions of rows
• Rows typically rolled out and replaced over
  time
• HG indexes are very slow to load/delete
• Loading time can steadily increases as rows are
  added
• Solution (with a caveat)
• Partition the table (Example time day, week,
  month)
• Build a view that is a Union of all the tables

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Data Loading Partitioned Fact Table
Big Fact Table
Accessed by View
Create View bigtable as Select from t1 Union
All Select from t2 Union All Select from t3
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Data Loading Why Partitioning?

• Loads are faster and predictable
• x million rows will load consistently
• IQ may process the Union All in parallel
• As long as cpu resources are available
• To roll data out, truncate one table
• Truncate table is much faster than Delete
• No changes to DDL required
• Load new data into the empty (truncated) table

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Data Extraction

• For fastest data unloads use the TEMP_EXTRACT
  options
• Can unload data in ASCII or BINARY format
• Recommend BINARY format as it is faster to reload
  into IQ-M
• Great way to archive portions of the database
• Can unload to one or more files, serially
• Avoid using ISQL or DBISQL redirection to a file
• Much slower than fast unloads

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Maintenance Tasks Database Consistency Checks

• The routine to check the database for potential
  corruptions is SP_IQCHECKDB
• There are no run-time options for this command,
  however the DBCC options control the behavior of
  the SP_IQCHECKDB command
• Recommendations
• Run Level 1 DBCCs every 1 to 4 weeks (will
  process 1-2 GB per second)
• Run Level 2 DBCCs every 1 to 3 months (will
  process 50-100 MB per second)

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Maintenance Tasks Parallel Create index

• Create Multiple Indexes in a batch
• Syntax
• BEGIN PARALLEL IQ
• Create HG Index
• Create LF Index
• END PARALLEL IQ
• Recommendation
• Create no more indexes in a batch than you have
  cpu's
• Note Two indexes on same column will be serial

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Maintenance Tasks Setting the IQ Caches

• Start by allocating memory to caches
• 40 IQ Main Cache
• 60 IQ Temporary Cache
• Adjust allocations from here based on monitoring
• Number of HG indexes in a table may alter this
  plan for loading data

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Maintenance Tasks IQ Monitoring

• IQ Monitor is a diagnostic tool for DBAs
• It collects and reports internal counters from
  the IQ Buffer Caches
• Main Cache interaction with the IQ Store
• Temporary Cache interaction with the IQ Temp
  Store
• IQ Monitor offers a series of views of the
  counters to showing differing aspects of the
  server and buffer cache workload

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Maintenance Tasks IQ Monitoring

• Provides different views of buffer activity
• summary report of both caches
• detailed report of one cache
• i/o activity of a cache
• a debug report of all buffer cache activity
• You must specify an option when you start the
  monitor to specify what view to monitor
• One Monitor may be running for a cache
• May have one for each (Main Temp)

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Managing Memory Inventory Your System Memory

• Assess whats running and how much memory it uses
  (exclusive of IQ-M)
• Typically these include
• Operating System
• OLAP Servers
• Middleware
• Other applications

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Managing Memory

• Deduct that total from RAM
• Allow 20 for File System Cache
• If using file systems
• Deduct another 10 (just in case)
• The rest is for IQ and IQ Caches
• A picture tells this story

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Memory The Big Picture

• Start with the O/S and other applications
• Determine what the IQ server needs (normal load)
• IQ Overhead (Heap for loading)
• Allocate IQ Caches
• 40 IQ Main Cache
• 60 IQ Temp Cache

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Best Practices for Implementing with Adaptive
Server IQ
Session E110
Questions?