sql - informix profiling tools to measure the query performance -


i have performance issues concerning informix queries .

so ask profiling tools enable me revise queries ..

from here:-

the comprehensive tool informix provides collecting detailed sql query plans , execution statistics set explain utility. utility generate file called sqexplain.out, , records in detail every step of query execution. in addition provides estimated costs of query , estimates query results. examining set explain output file, can determine if steps can taken improve performance of query. following example shows set explain output pretty complex query:

select --+avoid_full(omchn)+avoid_full(daphn)                 omchn.omc_hn_uanc,                 nvl(daphn.gtt_version,"0000000000000000000"),                 nvl(idachn.egt4_version,"0000000000000000000"),                 nvl(ihlrhn.hlr_timestamp,"00000000000000"),                 vsgw_hn.hn_igw_uanc,                 nvl(vsgw_hn.hn_igw_version, "00000000000000")            omchn, daphn, idachn, ihlrhn, vsgw_hn           daphn.dap_hn_inst  = omchn.omc_hn_inst             , idachn.idac_hn_inst = omchn.omc_hn_inst             , ihlrhn.hlr_hn_inst = omchn.omc_hn_inst             , vsgw_hn.vsgw_hn_inst = omchn.omc_hn_inst  directives followed: avoid_full ( omchn ) avoid_full ( daphn ) directives not followed:  estimated cost: 8 estimated # of rows returned: 1    1) root.idachn: sequential scan    2) root.daphn: index path      (1) index keys: dap_hn_inst   (serial, fragments: all)         lower index filter: root.daphn.dap_hn_inst = root.idachn.idac_hn_inst nested loop join    3) root.vsgw_hn: sequential scan nested loop join    4) root.omchn: index path                  filters: root.vsgw_hn.vsgw_hn_inst = root.omchn.omc_hn_inst             (1) index keys: omc_hn_inst   (serial, fragments: all)       lower index filter: root.idachn.idac_hn_inst = oot.omchn.omc_hn_inst nested loop join       5) root.ihlrhn: index path              (1) index keys: hlr_hn_inst   (serial, fragments: all)       lower index filter: root.ihlrhn.hlr_hn_inst = root.omchn.omc_hn_inst nested loop join

Comments

Post a Comment

Popular posts from this blog

java.util.scanner - How to read and add only numbers to array from a text file -

i'm learning java , have question regarding reading file want read numbers file contains strings well. here example of file: 66.56 "3 java 3-43 5-42 2.1 1 and here coding: public class test { public static void main (string [] args){ if (0 < args.length) { file x = new file(args[0]); try{ scanner in = new scanner( new fileinputstream(x)); arraylist<double> test = new arraylist<>(); while(in.hasnext()){ if(in.hasnextdouble()){ double f=in.nextdouble(); test.add(f);} else {in.next();} } catch(ioexception e) { system.err.println("exception during reading: " + e); } } my problem add 66.56,2.1 , 1 doesn't add 3 after "3 or ignores 3-43 , 5-42 can tell me how skip strings , add doubles here? thanks all said 3 ie; "3, 3-43 , 4-42 strings either u read string , split , check number @ " , - or put in space between characters , integers. jvm after compilation tre...
Read more

rewrite - Trouble with Wordpress multiple custom querystrings -

i'm working on adding multiple querystring , doesn't seem work. i've found codes seems work others might i'm missing something. i want like: http://mydomain.com/board/?getyear=2013&getsometext2=sometext to http://mydomain.com/board/2013/sometext/ i added code below functions.php file. doesn't seem work should though. this works. echoing querystring gets both variable without problem. http://mydomain.com/board/2013/sometext/ but doesn't. tested querystring vis isset() seems nothing being set/get http://mydomain.com/board/2013/ function add_query_vars($vars) { $vars[] = "getyear"; $vars[] = "getsometext2"; return $vars; } add_filter('query_vars', 'add_query_vars'); function add_rewrite_rules($arules) { $anewrules = array('board/([^/]+)/([^/]+)/?$' => 'index.php?pagename=board&getyear=$matches[1]&getsometext2=$matches[2]'); $arules = $a...
Read more