quantize.md

Quantize

The QUANTIZE directive quantizes a column based on specified ranges.

Syntax

copy <source> <destination> <range_lower1:range_upper1=value>[,<range_lower2:range_upper2=value>*]

• The <source> column is the column to be quantized
• The <destination> column is the column where the results of the quantization are to be written

The QUANTIZE directive quantizes based on values of the <source> column.

Usage Notes

The QUANTIZE directive quantizes based on values from the <source> column into the <destination> column.

Using the list of ranges specified in the options, it will <value> into the <destination> column if the source value matches one of the ranges.

The last range that the source value matches is the one that will be used.

If a range limit is missing, that range will fail without an error or exception.

If the <destination> column already exists, the directive will override any existing data in that column.

The values in the <source> column must be numeric.

The <value> of the range can be numeric or a string.

Example

Using these records as an example:

[
  {
    "body": 1
  },
  {
    "body": 2
  },
  {
    "body": 3
  },
  {
    "body": 4
  },
  {
    "body": 5
  },
]

Applying this directives:

quantize body body_q 1:2=20,3:4=40,5:10=max

would result in these records:

[
  {
    "body": 1,
    "body_q": 20
  },
  {
    "body": 2,
    "body_q": 20
  },
  {
    "body": 3,
    "body_q": 40
  },
  {
    "body": 4,
    "body_q": 40
  },
  {
    "body": 5,
    "body_q": "max"
  },
]