⚡️ v2.7.7 Index performance improvements, add drop indices and index pipes, and more.

v2.7.7

• Add actions drop indices and index pipes.
  You may now drop and create indices on pipes with the actions drop indices and index pipes or the pipe methods drop_indices() and create_indices():

  import meerschaum as mrsm
  
  pipe = mrsm.Pipe('demo', 'drop_indices', columns=['id'], instance='sql:local')
  pipe.sync([{'id': 1}])
  print(pipe.get_columns_indices())
  # {'id': [{'name': 'IX_demo_drop_indices_id', 'type': 'INDEX'}]}
  
  pipe.drop_indices()
  print(pipe.get_columns_indices())
  # {}
  
  pipe.create_indices()
  print(pipe.get_columns_indices())
  # {'id': [{'name': 'IX_demo_drop_indices_id', 'type': 'INDEX'}]}

• Remove CAST() to datetime with selecting from a pipe's definition.
  For some databases, casting to the same dtype causes the query optimizer to ignore the datetime index.

• Add INCLUDE clause to datetime index for MSSQL.
  This is to coax the query optimizer into using the datetime axis.

• Remove redundant unique index.
  The two competing unique indices have been combined into a single index (for the key unique). The unique constraint (when upsert is true) shares the name but has the prefix UQ_ in place of IX_.

• Add pipe parameter null_indices.
  Set the pipe parameter null_indices to False for a performance improvement in situations where null index values are not expected.

• Apply backtrack minutes when fetching integer datetimes.
  Backtrack minutes are now applied to pipes with integer datetimes axes.