Databases
StackOverflow2013
Postsdbo
POPyTables in-kernel search on Time64Col
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POPyTables in-kernel search on Time64Col
    primarykey
    data
    text
    <p>I'm using PyTables 2.4.0 and Python 2.7 I've got a database that contains the following typical table:</p> <pre><code>/anc/asc_wind_speed (Table(87591,), shuffle, blosc(3)) 'Wind speed' description := { "value_seconds": Time64Col(shape=(), dflt=0.0, pos=0), "update_seconds": Time64Col(shape=(), dflt=0.0, pos=1), "status": UInt8Col(shape=(), dflt=0, pos=2), "value": Float64Col(shape=(), dflt=0.0, pos=3)} byteorder := 'little' chunkshape := (2621,) autoIndex := True colindexes := { "update_seconds": Index(9, full, shuffle, zlib(1)).is_CSI=True, "value": Index(9, full, shuffle, zlib(1)).is_CSI=True} </code></pre> <p>I populate the timestamp columns using float seconds.</p> <p>The data looks OK in my IPython session:</p> <pre><code>array([(1343779432.2160001, 1343779431.8529999, 0, 5.2975000000000003), (1343779433.2190001, 1343779432.9430001, 0, 5.7474999999999996), (1343779434.217, 1343779433.9809999, 0, 5.8600000000000003), ..., (1343866301.934, 1343866301.5139999, 0, 3.8424999999999998), (1343866302.934, 1343866302.5799999, 0, 4.0599999999999996), (1343866303.934, 1343866303.642, 0, 3.7825000000000002)], dtype=[('value_seconds', '&lt;f8'), ('update_seconds', '&lt;f8'), ('status', '|u1'), ('value', '&lt;f8')]) </code></pre> <p>.. but when I try to do an in-kernel search using the indexed column 'update_seconds', everything goes pear-shaped:</p> <pre><code>len(wstable.readWhere('(update_seconds &lt;= 1343866303.642)')) 0 </code></pre> <p>ie I get 0 rows returned when I was expecting all 87591 of them. Occasionally I do manage to get some rows with a '>=' query, but the timestamp columns are then returned as huge floats (~10^79). It seems that there is some implicit type-conversion going on that causes the Time64Col values to be misinterpreted. Can someone spot my mistake, or should I forget about Time64Cols and convert them all to Float64 (and how do I do this?) </p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USProfCalculus
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. This table or related slice is empty.
 

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