Questions tagged [indexing]

Indexing is the almost most important part of data to get an efficient, properly storing and retrieval data from mediums

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Primary indexes [closed]

I would like to ask you two questions about indexing: 1) Since a primary index, or clustering index, stores the tuples of a relation in the primary index itself (but primary index might also be ...
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Primary indexes and index-sequential files

I am studying the physical organization of databases and right now I trying to understand the concept of primary index or clustering index. The book states the primary index can be realized by storing ...
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Indexing tensors in custom loss function with Keras

I'm using a custom loss function in Keras. This is the function: ...
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DBMS - Indexed Sequential Files

If i already have a primary index on a file, what is the purpose of ordering also the records of the file by primary key ? Can't i simply use the primary index to get a fast access to records without ...
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Utility of using a Primary Index in a relational dbms

If the records stored in each block are ordered by the primary key, what is the vantage of using a primary index? In fact, without a primary index, I still can do a binary search: taking the block in ...
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Vector de-factorization

Suppose one has a data set with a column/vector which consists of factor-like character strings: ["a level", "b value", "c bound", "a level", ...] For conversion ...
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Implementing Data Catalog from scratch

I have a requirement of ingesting huge amount of user specific data and then searching on it. Trying to be low cost solution, I am leaning towards creating Kafka based ingestion pipelines and ...
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1answer
6k views

How to create dictionary with multiple keys from dataframe in python?

I have a pandas dataframe as follows, I want to convert it to a dictionary format with 2 keys as shown: ...
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1answer
105 views

Pandas dataframe with multiple hierarchical indices

I have a data frame which looks like this ...
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2answers
114 views

Pandas: Assign back to table from grouping by column and index

I am trying to implement Exponential Moving Average calculation on a DataFrame. The formula is An additional complication is that my table is grouped and there is ...
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1answer
12k views

How to resolve too many indices for array Index Error

I'm performing a binary classification in Keras and attempting to plot the ROC curves. When I tried to compute the fpr and tpr metrics, I get the "too many indices for array" error. Here is my code: <...
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1answer
5k views

convert single index pandas data frame to multi-index

I have a data frame with following structure: ...
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2answers
17k views

Counting indexes in pandas

I feel like this is a rudimentary question but I'm very new to this and just haven't been able to crack it / find the answer. Ultimately what I'm trying to do here is to count unique values on a ...
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1answer
485 views

Why keep vocabulary and posting list separate in a search engine

I am taking a class in information retrieval. We learned that the index of a search engine has (possibly among other things): A vocabulary mapping terms to their statistics (frequency, type, ...) and ...
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1answer
26 views

Index for efficient argmax(w.x) query ~ 20d

I'm looking for a spatial index that can efficiently find the most extreme n points in a certain direction, i.e. for a given w, find x[0:n] in the dataset where x0 gives the largest value of w.x and ...
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800 views

What is the most efficient data indexing technique

As we all know, there are some data indexing techniques, using by well-known indexing apps, like Lucene (for java) or Lucene.NET (for .NET), MurMurHash, B+Tree etc. For a No-Sql / Object Oriented ...