db2advis 的學習使用

db2advis is a tool that recommends database objects based
 on an existing database and a set of queries.

  SYNTAX:

 db2advis -d <db name> [-t <time>] [-l <disk_space>]
          -s "sql stmt" | -i <infile> | -w <workload name> | -g | -qp [<starttime> [<endtime>]] | -wlm <evmonname> [<workload or serviceclass>] [<starttime> [<endtime>]]
         [ -[user|a] <username> [/<password>] ]
         [ -[type|m] <advis_type> ]
         [ -[compress|k] <compression level> ]
         [ -[tbsp|b] <MQT creation table space> ]
         [ -[simtbsp|c] <simulation table space> ]
         [ -[schema|n] <schema name> ]
         [ -[qualifier|q] <qualifying schema name>]
         [ -[script|o] <output script> ]
         [ -[password|x] ] [ -[sample|r] ] [ -[deferred|u] ] [ -nogen ] [ -[drop|f] ]
         [ -[keep|p] ] [ -delim <char> ]
         [ -mdcpctinflation <percent> ] [ -tables <table_predicate_clause> ]

 

  NOTE 1: only one of the following six options
       can be used:  [stmt,file,workload,pkg,qp,wlm]
  NOTE 2: -tbsp, -simtbsp, -schema and -sample can only be specified when MQTs are to be selected

 where:

    -[db|d]          database name.
    -[keep|p]        keep plans in explain tables.
    -[timelimit|t]   maximum duration for db2advis to run, in minutes.
                     default is unlimited (algorithm execution continues until
                     no changes to the recommendations is possible).
                     a value of 0 means unlimited duration.
    -[disklimit|l]   maximum disk space in megabytes.  default is
                     20% of total database size.
    -[stmt|s]        recommend database objects for this SQL statement.
    -[file|i]        get SQL from this input file.
    -[workload|w]    get SQL from rows in the ADVISE_WORKLOAD table,
                     specified by matching WORKLOAD_NAME.
    -[pkg|g]         get workload from dynamic package cache
    -qp              get workload from query patroller table.
                     Optionally, a <starttime> and <endtime> timestamp can
                     be added to get statements on or after the <starttime>
                     and optional on or before the <endtime>.
    -wlm             get workload from WLM activity tables for event name <evmonname>.
                     Optionally, a <starttime> and <endtime> timestamp can
                     be added to get statements on or after the <starttime>
                     and optional on or before the <endtime>.
                     Note that the optional <workload or serviceclass> is
                     of the form
                            {WORKLOADNAME|WL} <workloadname>
       
                                 OR
       
                            {SERVICECLASS|SC} <superclassname>[,<subclassname>].
    -[script|o]      place the database objects creation script in a file.
    -[user|a]        username to connect with. (optional password)
    -[type|m]        advise type.
                            Subset of:
                                 I - for index selection,
                                 M - for MQT selection,
                                 C - for Multi-dimensional Clustering selection,
                                 P - for partitioning selection,
                            Default is I
                         Example: MICP - for ALL selections.
    -[tbsp|b]        MQT creation tbspace name (default is USERSPACE1)
    -[simtbsp|c]     simulation table space name that is defined only on the catalog node
    -[schema|n]      schema name that is used to define new MQTs
    -[qualifier|q]   schema name used to qualify unqualified tables
    -[sample|r]      gets more statistics for MQT.
    -[compress|k]    specifies compression OFF, LOW, MED, or HIGH. default is MED
    -[drop|f]        drops previously existing simulated catalog tables
    -[deferred|u]    specified that immediate and deferred MQTs are to be output. Default is immediate.
    -[nogen]         indicates that generated columns are not to be included in MDC recommendations
    -[password|x]    indicates that the password will be read from stdin
    -delim <char>    specifies <char> to be used as the statement delimiter for the
                     workload file input. Default delimiter is ';'
    -mdcpctinflation <percent>  Specifies the maximum percentage that the table
                     disk size can increase in an MDC recommendation.
    -tables <table_predicate_clause>  Indicates that only a subset of all
                     existing tables should be considered. The
                     <table_predicate_clause> must be a predicate that can
                     be used in the WHERE clause of a query on SYSCAT.TABLES.
                     this option does not apply to recommendations about new
                     MQTs.

 

  EXAMPLE:

 Create an input file called db2advis.in with the following 5 lines:
 --#SET FREQUENCY 100
 SELECT COUNT(*) FROM EMPLOYEE;
 SELECT * FROM EMPLOYEE WHERE LASTNAME='HAAS';
 --#SET FREQUENCY 1
 SELECT AVG(BONUS), AVG(SALARY) FROM EMPLOYEE
          GROUP BY WORKDEPT ORDER BY WORKDEPT;

 run the following command and let it finish
 db2advis -d sample -i db2advis.in -t 5

 for bigger workloads, the program will take longer.