Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>The biggest/largest integer that can be stored in a double without losing precision is the same as the largest possible value of a double. That is, <code>DBL_MAX</code> or approximately 1.8&nbsp;×&nbsp;10<sup>308</sup> (if your double is an IEEE 754 64-bit double). It's an integer. It's represented exactly. What more do you want?</p> <p>Go on, ask me what the largest integer is, such that it <em>and all smaller integers</em> can be stored in IEEE 64-bit doubles without losing precision. An IEEE 64-bit double has 52 bits of mantissa, so I think it's 2<sup>53</sup>:</p> <ul> <li>2<sup>53</sup> + 1 cannot be stored, because the 1 at the start and the 1 at the end have too many zeros in between. </li> <li>Anything less than 2<sup>53</sup> can be stored, with 52 bits explicitly stored in the mantissa, and then the exponent in effect giving you another one. </li> <li>2<sup>53</sup> obviously can be stored, since it's a small power of 2.</li> </ul> <p>Or another way of looking at it: once the bias has been taken off the exponent, and ignoring the sign bit as irrelevant to the question, the value stored by a double is a power of 2, plus a 52-bit integer multiplied by 2<sup>exponent&nbsp;−&nbsp;52</sup>. So with exponent 52 you can store all values from 2<sup>52</sup> through to 2<sup>53</sup>&nbsp;−&nbsp;1. Then with exponent 53, the next number you can store after 2<sup>53</sup> is 2<sup>53</sup> + 1&nbsp;×&nbsp;2<sup>53 − 52</sup>. So loss of precision first occurs with 2<sup>53</sup> + 1.</p>
    singulars
    1. This table or related slice is empty.
    1. PObiggest integer that can be stored in a double
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USSteve Jessop
    1. USSteve Jessop
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PObiggest integer that can be stored in a double
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. CO+1 Good job noticing that the question did not really mean what the asker probably intended and providing both answers ("technically correct" and "probably expected").
      singulars
      1. PO
      1. USPascal Cuoq
    2. COOr "messing about" and "trying to help" as I tend to call them :-)
      singulars
      1. PO
      1. USSteve Jessop
    3. COI have juste added more precision in the description of my question. I was talking about the biggest "no-floating" integer.
      singulars
      1. PO
      1. USFranck Freiburger
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload