Strange index values with numerics

On Mon, Aug 27, 2018 at 10:41 PM Zachary N. Dean <contact at zadean.com> wrote: > > Hi, > > I was recently taking a look into the index data files (for reasons) and came across something that I found strange... > > > > When numeric values are in nodes they are put into the index with min/max and distinct token values, which is cool… > > What's strange is, when negative integer values are in text and attribute nodes the index contains the minimum value correctly, but the maximum value is '4.9E-324' ([0,0,0,0,0,0,0,1]). > > This doesn't seem to happen with positive values. > > Now, with small value ranges I assume this is okay, but with many values I would imagine it could slow things down. > > > > Not sure if this is a bug or a feature, so I figured I'd bring it up. > > > > Here an example: > > <r> > > <a>-1</a> > > <b>0</b> > > <c>1</c> > > <d>-50000</d> > > <d>-49000</d> > > <e>2</e> > > <e>3</e> > > <f a="-1"/> > > <g>-1</g> > > <g>1</g> > > </r> > > > > I would have assumed that the index would see that element "d" has a min of -50000 and a max of -49000. > > > > Here the index infos: > > > > Elements > > - Structure: Hash > > - Entries: 8 > > g 2x, 2 distinct integers [-1, 1], leaf > > e 2x, 2 distinct integers [2, 3], leaf > > d 2x, 2 distinct integers [-50000, 4.9E-324], leaf > > c 1x, integer [1, 1], leaf > > f 1x, leaf > > r 1x > > a 1x, integer [-1, 4.9E-324], leaf > > b 1x, integer [0, 4.9E-324], leaf > > > > Attributes > > - Structure: Hash > > - Entries: 1 > > a 1x, integer [-1, 4.9E-324], leaf > > > > > > If it's a feature, then cool. Keep on rockin'! If not, then I hope this helps a little. > > > > Thanks, > > > > Zack Dean

De : BaseX-Talk [mailto:basex-talk-bounces at mailman.uni-konstanz.de] De la part de Christian Grün Envoyé : mardi 28 août 2018 09:07 À : Zachary N. Dean Cc : BaseX Objet : Re: [basex-talk] Strange index values with numerics Hi Zack, I helps indeed! I learnt that -Double.MAX_VALUE is smaller than Double.MIN_VALUE in Java. The fix turned out to be pretty straightforward [1]; a new stable snapshot is available [2]. Have fun, Christian [1] https://github.com/BaseXdb/basex/issues/1616 [2] http://files.basex.org/releases/latest/ On Mon, Aug 27, 2018 at 10:41 PM Zachary N. Dean <contact at zadean.com> wrote: > > Hi, > > I was recently taking a look into the index data files (for reasons) and came across something that I found strange... > > > > When numeric values are in nodes they are put into the index with min/max and distinct token values, which is cool… > > What's strange is, when negative integer values are in text and attribute nodes the index contains the minimum value correctly, but the maximum value is '4.9E-324' ([0,0,0,0,0,0,0,1]). > > This doesn't seem to happen with positive values. > > Now, with small value ranges I assume this is okay, but with many values I would imagine it could slow things down. > > > > Not sure if this is a bug or a feature, so I figured I'd bring it up. > > > > Here an example: > > <r> > > <a>-1</a> > > <b>0</b> > > <c>1</c> > > <d>-50000</d> > > <d>-49000</d> > > <e>2</e> > > <e>3</e> > > <f a="-1"/> > > <g>-1</g> > > <g>1</g> > > </r> > > > > I would have assumed that the index would see that element "d" has a min of -50000 and a max of -49000. > > > > Here the index infos: > > > > Elements > > - Structure: Hash > > - Entries: 8 > > g 2x, 2 distinct integers [-1, 1], leaf > > e 2x, 2 distinct integers [2, 3], leaf > > d 2x, 2 distinct integers [-50000, 4.9E-324], leaf > > c 1x, integer [1, 1], leaf > > f 1x, leaf > > r 1x > > a 1x, integer [-1, 4.9E-324], leaf > > b 1x, integer [0, 4.9E-324], leaf > > > > Attributes > > - Structure: Hash > > - Entries: 1 > > a 1x, integer [-1, 4.9E-324], leaf > > > > > > If it's a feature, then cool. Keep on rockin'! If not, then I hope this helps a little. > > > > Thanks, > > > > Zack Dean