bigdata

https://github.com/taosdata/TDengine/blob/develop/src/query/src/qAggMain.c

Passing argument pList of type tValuePair ** and argument 8 /* sizeof (tValuePair **) */ to function taosheapsort is suspicious. In this case, sizeof (tValuePair **) is equal to sizeof (tValuePair *), but this is not a portable assumption.

![image](https://user-images.githubusercontent.com/48907085/141933524-4f3ebf60-

Description
Trying to convert an "object" column to string fails.

Example code:

import vaex
import numpy as np

if __name__ == "__main__":
    arr = np.array([123, "test", None], dtype=object)
    df = vaex.from_arrays(test=arr)
    df['test'] = df['test'].astype('str')
    print(df.head())

Exception:

TypeError: to_string(): incompatible function argu

What would you like to be added:

Currently, there are few materials about job plugins(ssh/env/svc) such as scenarios, design and usages, expecially about the available parameters in these plugins.

Why is this needed:

We've got a lot of feedback about how to use the job plugins.

This is to track implementation of the ML-Features: https://spark.apache.org/docs/latest/ml-features

Bucketizer has been implemented in dotnet/spark#378 but there are more features that should be implemented.

• Feature Extractors
  • TF-IDF
  • Word2Vec (dotnet/spark#491)
  • CountVectorizer (https://github.com/dotnet/spark/p

especially for less obvious but lengthy code snippets!