The exchange of R data and Aster Database data is done by mapping an R data frame to an Aster Database table. The R program needs to be able to accept and map the input data to the right types, and the output from the R program should match what is specified in the OUTPUTS clause of the Stream function (except in the case of a “*” expression in the OUTPUTS clause, which expects data with the same types as the input data).
This table shows the recommended mapping of data types from R to Aster Database:
| R Type | SQL Type |
|---|---|
| integer | int2, int4 |
| numeric (double) | int8, float4, float8, float(p), numeric [(p,s)] |
| boolean | logical |
| bytea | object |
| everything else | character |
However, there are a few mapping issues that users need to be aware of, which are described in here.