oracle - Does a reverse key index help if i use an incremental sequence to insert subsequent values -

-

i understood basic rationale reverse key index reduce index contention. if have 3 numbers in index: 12345, 27999, 30632, can see if reverse these numbers, next number in sequence won't hit same leaf block.

but if numbers :12345,12346,12347, next numbers 12348,12349 (incremented 1) hit same leaf block if index reversed: 54321,64321,74321,84321,94321.

so how reverse index helping me? supposed particularly while using sequences

if we're talking sequence-generated value, can't @ 5 values , draw many conclusions. need think data has been inserted , data inserted in future.

assuming sequence started @ 12345, first 5 values inserted sequentially. sixth value 12350. reverse , 05321 go far left of index. you'd generate 12351. reverse 15321 , that's again toward left-hand side of index between first value generated (54321) , recent value (05321). sequence generates new values, they'll go further right until resets every 10 numbers , you're inserting far left-hand side of index again.


Comments

Post a Comment

Popular posts from this blog

java - JavaFX 2 slider labelFormatter not being used -

-
i have following code not label slider "foo50", etc... 1 expect setlabelformatter call, instead seems have no effect (the slider labelled 50, 100, etc , println's dont run). there missing? not implemented in default 2.2 skin? using oracle java 7 package javafxbugtest; import javafx.application.application; import javafx.scene.*; import javafx.scene.control.*; import javafx.stage.*; import javafx.util.stringconverter; public class javafxbugtest extends application { @override public void start(final stage primarystage) { slider cp = new slider(); cp.setlabelformatter(new stringconverter<double>() { @override public string tostring(double t) { system.out.println("nope?"); return "foo" + t.tostring(); } @override public double fromstring(string string) { system.out.println("he
Read more

Detect support for Shoutcast ICY MP3 without navigator.userAgent in Firefox? -

-
the current version of mozilla firefox 23.0.1, version not support play mp3 shoutcast streams tcp port different 80 (most common 8000 shoutcast 1.9.8). i use flash when mp3 support not available in html5 audio, way detect is: try{ var = document.createelement('audio'); r = !!(a.canplaytype && !!a.canplaytype("audio/mpeg; codecs=mp3").replace(/^no$/,'')) }catch(e){ r = false; } the support mp3 shoutcast streams in firefox added in version 24 . a.canplaytype("audio/mpeg; codecs=mp3") = in chrome , firefox, chrome support, firefox not support, due current code detect not work firefox. the current version of jquery support ie 6 1.10.2, version not has .browser i think "stylized" way testing features , not querying browsers / versions, notwithstanding here see hard not violate "principle". what "stylized" way of detect mp3 icy support without navigator.useragent in firefox? ther
Read more

web - SVG not rendering properly in Firefox -

-
i have problem svg renderring in firefox. whilst works in safari, chrome or in ie, doesn't work in firefox. inspecting element seems layers there, background visible if it's z-index higher z-index of others. rendered in firefox: svg logo in firefox link original source file: svg file thanks help. ps: used sketch 3 export svg. if helps somehow. you're experiencing bug 995813 . i fixed bug time ago change still making way through release process example display correctly firefox 31 onwards released on 22 july 2014. in meantime if move fill="white" <mask> element child <use> element work around firefox bug.
Read more