sybase asa - Adding index to the column already having an index -

-

there indexes available each columns. ex: indx1 on col1 , indx2 on col2. possible create again composite index indx3 combining col1 , col2? col1 , col2 used in condition. indx3 in effect?

yes, query optimizer best matching index. if include col1 , col2 in composite index , query (where) 2 fields use index.

you should consider throwing away index on col1 because composite index can used queries on col1 too. depends on sequence of columns in composite index: first column can queried without second one.


Comments

Post a Comment

Popular posts from this blog

java - Unable to make sub reports with Jasper -

-
i using jaspersoft studio create reports. having sub report in jasper main report. problem unable make work, because if add sub report detail band of main report, sub report generated number of times, row row, entire sub report repeated in number of pages. can't put in summery band due same reason. i unable put in column footer band or other footers because displays below error net.sf.jasperreports.engine.jrexception: net.sf.jasperreports.engine.jrruntimeexception: subreport overflowed on band not support overflow. @ com.jaspersoft.studio.editor.preview.view.control.reportcontroler.fillreport(reportcontroler.java:467) @ com.jaspersoft.studio.editor.preview.view.control.reportcontroler.access$18(reportcontroler.java:442) @ com.jaspersoft.studio.editor.preview.view.control.reportcontroler$4.run(reportcontroler.java:334) @ org.eclipse.core.internal.jobs.worker.run(worker.java:54) caused by: net.sf.jasperreports.engine.jrruntimeexception: subreport overflowe...
Read more

How can I utilize Yahoo Weather API in android -

-
Image
i want develop app using yahoo weather api android. want current , forecast weather details. i have tried different sources (e.g.: https://github.com/survivingwithandroid/weatherlib , getting error weatherlib api android , unable execute activity in android weatherlib ) , getting different errors m unable resplve. there can proper tutorial or guide! error: -17 08:50:48.961 3168-3168/com.survivingwithandroid.weather e/androidruntime﹕ fatal exception: main process: com.survivingwithandroid.weather, pid: 3168 java.lang.runtimeexception: unable start activity componentinfo{com.survivingwithandroid.weather/com.survivingwithandroid.weather.mainactivity}: java.lang.nullpointerexception: attempt invoke interface method 'boolean java.util.list.isempty()' on null object reference @ android.app.activitythread.performlaunchactivity(activitythread.java:2298) @ android.app.activitythread.handlelaunchactivity(activitythread.java:2360) @ android.app.activi...
Read more

Save and close a word document by giving a name in R -

-
i trying use 2 libraries ( descstool , r2wd ) in order descriptive analysis of dataset saved in folder exploration later. these steps trying library(desctools) library(r2wd) data(iris) <- ls() wrd <- getnewwrd(header=true) wdget() desc(get(i), plotit=true, wrd=wrd) wdsave(name="temp.doc", wdapp=.r2wd) wdquit() although word capturing output supposed be, cannot save word file giving name (e.g.: temp.doc). can shed light here? try library(desctools) wrd <- getnewwrd() desc(iris, wrd=wrd) wrd[["activedocument"]]$saveas2(filename="describe iris.docx") wrd$quit()
Read more