PostgreSQL Bugs

Collected from the PG bugs email list.

Bug ID16281
PG Version12.2
OSUbuntu 18.04.2
Opened2020-02-28 05:42:20+00
Reported byJustin
StatusNew

Body of first available message related to this bug follows.

The following bug has been logged on the website:

Bug reference:      16281
Logged by:          Justin
Email address:      (redacted)
PostgreSQL version: 12.2
Operating system:   Ubuntu 18.04.2
Description:        

Given this,

```
SELECT
LN(484990182159328900690402236933516249572671683638747490717351807610531884491845416923860371219625151551889257298200816555016472471293780254009492949585031653913930735918829139712249577547959394351523545901788627247613322896296041868431769047433229466634098452564756860190085118463828382895145244362033728480588969626012192733802377468089120757046364393407262957242230928854711898925295251902007136232994524624903257456111389508582206404271734668422903183500589303866613158037169610592539145461637447957948521714058034772237111009429638870236361143304703683377693378577075353794118557951847394763531830696578809001981568860219578880229402696449243344235099860421846016326538272155937175661905904288335499593232232926636205909086901191153907183842087577811871344870731324067822883041265129394268082883745408414994.8967939438561591657171240282983703914075472645212002662497023142663831371447287624846942598424990784971781730103682951722370983277124599054059027055336437808366784501932987082321905202623642371063626378290734289114618092750984153422293450048717769065428713836637664433167768445609659527458911187829232316677137895259433038764404970599325009178297626038331436654541552998098529141205301472138026818453893127265938030066392881979113522757891639646670670272542401773230506961559808927249585675430838495658225557294666522469887436551840596777627408780618586500922973500018513068499587683746133637919751545157547095670767246977244726331271787622126889459658539988980096764323712767863722912919120929339399753431689512753214200090670880647731689804555417871258907716687575767185444541243606329768784843125926070743277339790277626515824924290352180761378846035233155198504033292692893297993698953705472933411199778880561376633444249703838589180474329586470353212010427945060694794274109764269805332803290229)
```

Pg's result,

1864.3702986939570026328504202935192533137907736189919154633800554877738455118081651650863235106905871352085850240570561347180517240105510505203972860921397909573687877993477806728098306202020229409548306695695574102950949468160529713610952021974630774784174851619325758380143625473386495586347322798415543385655090746985183329114860118551572428921774322172798724455202876781611633419444058398798142214904998877857425038669920064728855823072107227506485770367799671977282350083029452784747350395161797215115525867416898416360638482342253129160308632504217096916335590470843180746834864303790913372081974355613359678634194879425862536147988835528973291020680020540866655622823550861337486588647231688134992810403147262346312159819432914207194632564009749236609081399504118359354620598232725290537215007867979331582119891661859015726276335168158288396939655310210558566592649049602925182137256134162660116182293851038854455437841571331011002023088829768308520393956515509475418031437505751407687618234418263

The last digit should be a 2, but pg thinks it's a 3,

If pg supported more than 1000 decimal places, the sequence should continue
...823441826 2 4968...

The 1000th fractional digit is 2.
The 1001st fractional digit is 4.
It should round the 1000th fractional digit to 2.

I'm not sure how much people care about results at 1000 decimal places,
though.
I'm not affected by this minor rounding error, I only discovered this while
working on something else.

-----

Other values that produce behaviour,

87190145885430429849953615409019208993240447426362428988181639909267773304254748257120061524000254226856815085523676417146197197996896030672521334101413071112068202429835905642444187493717977611730127126387257253646790849384975208460867137315507010888782632024640844766297185244443116696943912406389670302370461137850160539373600494054874979342373255280815156048999900951842673141766630630919020492255966628630634124452614590400422133958133100159154995520080124736657520969784129924799670552560034302960877087853678350801769339861812435411200669026902417951572668727488315537985378304242438181615160041688723201917323705450185975141141262578884689500612295576288125956289035673242989906973367691922065122033180281670221390667818909912035903387888639331486823729897326624516015340.0330856710565117793999512551468220085711713631167607285185762046751452975325645379302403715842570486302993296501788672462090620871511446272026693318239212657949496275318383141403236705902077406660768573015707706831878445598837931116223956945944726162551477136715847593742032488181481888084716920605114101902724395659898621880016853548602514706686907951229872573180602614761229992106144727082722940736406782659562775289407005631298246624198606031298081220736931229256511054595028182057216042683060059115371651410352645266000330509331097811566633211452233019461903115970558624057877018778178814946285827512359903934291318219271464841957435711594154280905473802599888081783098187210283997106131616471807951265003903143099667366508222327805543948921694362089860577380749774036318574113007382111997454202845559941557812813566442364810680529092880773126707073967537693927177460459341763934709686530005721141046645111784404932103241501569571235364365556796422998363930810983452790309019295181282099408260156

93936642222690597390233191619858485419795942047468396309991947772747208870873993801669373075421461116465960407843923269693395211616591453397070258466704654943689268224479477016161636938138334729982904232438440955361656138189836032891825113139184685132178764873033678116450665758561650355252211196676137179184043639278410827092182700922151290703747496962700158844772453483316974221113826173404445159281421213715669245417896170368554410830320000019029956317336703559699859949692222685614036912057150632902650913831404804982509990655560731349634628713944739168096272097122388116038119844786988276635032016787352796502360718569977397214936366251320294621522016.6483354941025384161536675750898007896744690911429670830432784905421638721478353275821072200938900938046264210604940707974410950770029535636602548377806284157951164875821446035013896786653932045182167021839184824627082391478016195098055107001433336586881395912782883663046617432598969149948351689103230162742769845955320418573803127107923535948653168889411316007796459064267436246637115946581149511513369842911210359447262641996566147462977170742544980481275049898092152042927981394239266559286915303786701737610786594006685748456635797125029722684151298695274097006242412384086302106763844070230264910503179385988626477852818174114043927841085089058972074427820150462261941575665882880501074676800316585217150509780489224388148722603385921057007086785238310735038314861960410473809826927329368597558806004392175746233568789445929554890241140656324160187253042639339549705859147930476532359840809944163908006480881926041259363654863689570520534301207043189181147254153307163555433328278834311658232337

Messages

DateAuthorSubject
2020-02-28 05:42:20+00PG Bug reporting formBUG #16281: LN() function inaccurate at 1000th fractional digit
2020-02-28 07:18:55+00Dean RasheedRe: BUG #16281: LN() function inaccurate at 1000th fractional digit
2020-02-28 15:39:01+00Tom LaneRe: BUG #16281: LN() function inaccurate at 1000th fractional digit
2020-02-29 17:16:02+00Dean RasheedRe: BUG #16281: LN() function inaccurate at 1000th fractional digit
2020-02-29 19:12:39+00Tom LaneRe: BUG #16281: LN() function inaccurate at 1000th fractional digit
2020-03-01 02:59:38+00Justin AnyhowStepRe: BUG #16281: LN() function inaccurate at 1000th fractional digit
2020-03-01 15:34:37+00Dean RasheedRe: BUG #16281: LN() function inaccurate at 1000th fractional digit