not query in lucene
A very late reply, but it might be useful for somebody else later: *:* AND NOT country:sweden IF I’m not mistaken this should do a logical “AND” with all documents and the documents with a country that is different from “sweden”.
indexing
Create a table and add indexes in a single migration with Sequelize
Yes, the methods can be chained. In your case you just perform the addIndex after createTable method return queryInterface.createTable(‘Todos’, { // columns… }).then(() => queryInterface.addIndex(‘Todos’, [‘author_id’, ‘title’])) .then(() => { // perform further operations if needed });
How does a geospatial index work? [closed]
Depending on the data type and usage pattern, either an R-Tree or variant (R*, R+) or a quadtree or perhaps even a kd-tree.
R-Tree and Quadtree Comparison
Here’s paper which has pretty nice comparison of QuadTrees and R Trees: Quadtree and R-tree Indexes in Oracle Spatial: A Comparison using GIS Data Some differences: Quadtrees require fine-tuning by choosing appropriate tiling level in order to optimize performance. No specific tuning is required for R-Trees. Quadtree can be implemented on top of existing B-tree. … Read more
pandas – how to access cell in pandas, equivalent of df[3,4] in R
You can use iloc (to get by position): df.iloc[3,4] I recommend reading the indexing section of the docs.
Index in Parquet
Update Dec/2018: Parquet Format version 2.5 added column indexes. https://github.com/apache/parquet-format/blob/master/CHANGES.md#version-250 See https://issues.apache.org/jira/browse/PARQUET-1201 for list of sub-tasks for that new feature. Notice that this feature just got merged into Parquet format itself, it will take some time for different backends (Spark, Hive, Impala etc) to start supporting it. This new feature is called Column Indexes. Basically … Read more
In PANDAS, how to get the index of a known value?
There might be more than one index map to your value, it make more sense to return a list: In [48]: a Out[48]: c1 c2 0 0 1 1 2 3 2 4 5 3 6 7 4 8 9 In [49]: a.c1[a.c1 == 8].index.tolist() Out[49]: [4]
Proper terminology, should I say indexes or indices? [closed]
“Indices” is the mathematical formulation whereas in publishing they use “indexes” (which is probably why so many people in IT consider “indices” to be more correct than “indexes”). I think that a table index is analogous to an index in a book rather than an exponent in maths, so the publishing variant is the appropriate … Read more
Adjust Single Value within Tensor — TensorFlow
UPDATE: TensorFlow 1.0 includes a tf.scatter_nd() operator, which can be used to create delta below without creating a tf.SparseTensor. This is actually surprisingly tricky with the existing ops! Perhaps somebody can suggest a nicer way to wrap up the following, but here’s one way to do it. Let’s say you have a tf.constant() tensor: c … Read more
Solr commit and optimize questions
A little more detail on Commit/Optimize: Commit: When you are indexing documents to solr none of the changes you are making will appear until you run the commit command. So timing when to run the commit command really depends on the speed at which you want the changes to appear on your site through the … Read more