Hi John,
Thanks for your response. Is there a way to force these indices to be
created for the string column programmatically? When I add my string
column to the table I have tried doing the following:
table->addColumn("attr", ibis::TEXT, "index=keywords"); <---------- I've
also tried just the word "keywords" here.
But every time the partition generates indices, the partition file always
gives me:
Begin Column
name = "attr"
description = attr
data_type = "TEXT"
index=noindex
End Column
I would like to generate the index at the time I generate all the others
programmatically.
Thanks,
Teryl
On Thu, Jul 28, 2011 at 9:08 PM, K. John Wu <[email protected]> wrote:
> Hi, Teryl,
>
> FastBit supports strings in two different ways, as categorical values
> (keys) or text. For categorical values, the string in each row is treated
> as an atomic value. FastBit will build a dictionary for the values and
> build an index. Let's say the column name is 'mykey', in the data
> directory, you should see, four files named as follows
>
> mykey, mykey.sp, mykey.dic, mykey.idx.
>
> They are the original string values (in raw binary with nil terminators),
> the starting positions of the strings, the dictionary, and the index.
>
> For text values, by default, no index is built. The only index that is
> supported is a keyword index. In this case, the text in each row is broken
> into words and the index records the appearances of each word (also called
> keyword) in any row. To tell FastBit to build a keyword index, modify the
> indexing specification of the specific column in the metadata file -part.txt
> to say something like
>
> index=keywords
>
> in the context of a column, the specification of the column in a -part.txt
> file might look like the following
>
> Begin Column
> name = mytext
> description = a free-form text describing the column content
> type = TEXT
> index = keywords
> End Column
>
>
> Please feel free to let us know if you have more questions.
>
> John
>
>
>
>
>
> On 7/28/11 12:14 PM, Teryl Taylor wrote:
>
>> Hi John,
>>
>> I've created a column in my database that is a column of strings -
>> high cardinality (500,000 to 1,000,000). I call buildIndexes on the
>> partition, and it seems to build indices for all columns except for
>> the string column. Are string indices not supported? Or do I have to
>> do something special to get them to generate?
>>
>>
>> Best Regards,
>>
>> Teryl
>>
>>
>>
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>
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