The DWT function has a required input table (or view) and an optional wavelet filter table. If you omit the wavelet filter table, you must specify the Wavelet argument.
The input table can contain at most 1594 columns. The function assumes that each sequence can be fitted into the memory of the worker. The following table describes the input table columns that you can or must specify with arguments. The input table can have additional columns, but the function ignores them.
Column Name | Data Type | Description |
---|---|---|
partition_column | INTEGER, SMALLINT, BIGINT, NUMERIC [(p, s)], TEXT, VARCHAR, VARCHAR(n), UUID, or BYTEA | Optional. Sequence identifier of the sequence to which the data belongs. Rows with the same partition column values belong to the same sequence. If the input table has multiple partition columns, the function treats the first one as the distribute key of the output and meta tables. |
sort_column | INTEGER, SMALLINT, BIGINT, BIGSERIAL, DOUBLE PRECISION, NUMERIC [(p, s)], SERIAL, TIME, or TIMESTAMP | Position of the data in the sequence to which it belongs. |
input_column | INTEGER, SMALLINT, BIGINT, BIGSERIAL, DOUBLE PRECISION, NUMERIC [(p, s)], or SERIAL | Data to be transformed—numeric values between -1e308 and 1e308 (or NULL, which the function treats as 0). |
Column Name | Data Type | Description |
---|---|---|
filtername | VARCHAR | Wave filter name from the following table. |
filtervalue | VARCHAR | Decomposed or reconstructed wavelet filter, represented as a comma-separated sequence; the conjugated scale coefficients for the orthogonal wavelet. For example: -0.1294095225512604, 0.2241438680420134, 0.8365163037378081, 0.4829629131445342 For details, see the following table. |
filtername | filtervalue |
---|---|
lowpassfilter | Decomposed low-pass filter, represented as a comma-separated sequence; the conjugated scale coefficients for the orthogonal wavelet. For example: -0.1294095225512604, 0.2241438680420134, 0.8365163037378081, 0.4829629131445342 |
highpassfilter | Decomposed high-pass filter, represented as a comma-separated sequence; the conjugated wavelet coefficients for the orthogonal wavelet. For example: -0.4829629131445342, 0.8365163037378081, -0.2241438680420134, -0.1294095225512604 |
ilowpassfilter | Reconstructed low-pass filter, represented as a comma-separated sequence; the scale coefficients for the orthogonal wavelet. For example: 0.4829629131445342, 0.8365163037378081, 0.2241438680420134, -0.1294095225512604 |
ihighpassfilter | Reconstructed high-pass filter, represented as a comma-separated sequence; the wavelet coefficients for the orthogonal wavelet. For example: -0.1294095225512604, -0.2241438680420134, 0.8365163037378081, -0.4829629131445342 |