SAS 9.1.3 Language Reference: Concepts, Third Edition, Volumes 1 and 2
What Types of Processing Does CEDA Support?
CEDA supports SAS 7 and later SAS files that are created in directory-based operating environments like UNIX, Windows, and OpenVMS Alpha. CEDA provides the following SAS file processing for these SAS engines:
| BASE | default engine for Base SAS in SAS 9 (V9), SAS 8 (V8), and SAS 7 (V7). |
| SOCKET | TCP/IP port engine for SAS/CONNECT. |
| TAPE | sequential engine for SAS 9 (V9TAPE), SAS 8 (V8TAPE), and SAS 7 (V7TAPE). |
| SAS File Type | Engine | Supported Processing |
|---|---|---|
| SAS data file | BASE, TAPE, SOCKET | input and output [1] processing |
| PROC SQL view | BASE | input processing |
| SAS/ACCESS view for Oracle or SYBASE | BASE | input processing |
| MDDB file [2] | BASE | input processing |
|
[1] For output processing that replaces an existing SAS data file, there are behavioral differences. See "Behavioral Differences for Output Processing" on page 581.
[2] CEDA supports SAS 8 and later MDDB files. | ||
Behavioral Differences for Output Processing
For output processing that replaces an existing SAS data file, there are behavioral differences regarding these attributes:
encoding
-
The BASE engine uses the encoding of the existing file; that is, the encoding is cloned.
-
The TAPE engine uses the current SAS session encoding.
-
For both the BASE and TAPE engines, the COPY procedure uses the encoding of the file from the source library (that is, the file being copied ), regardless of whether the file existed in the target library.
data representation
The BASE and TAPE engines use the data representation of the native environment, except with the COPY procedure, which by default uses the data representation of the file being copied.
Restrictions for CEDA
CEDA has the following restrictions:
-
CEDA does not support DATA step views, SAS/ACCESS views that are not for SAS/ACCESS for Oracle or SYBASE, SAS catalogs, stored compiled DATA step programs, item stores, DMDB files, FDB files, or any SAS file that was created with a version of SAS prior to SAS 7.
-
Update processing is not supported.
-
Indexes are not supported. Therefore, WHERE optimization with an index is not supported.
-
CEDA is supported only for directory-based file systems. On OS/390 or z/OS, only HFS or zFS (UNIX file systems) libraries support CEDA. In particular, CEDA is not supported for bound libraries on z/OS. For additional information, see "Library Implementation Types for Base and Sequential Engines" in SAS Companion for z/ OS .
-
Because the BASE engine translates the data as the data is read, multiple procedures require SAS to read and translate the data multiple times. In this way, the translation could affect system performance.
-
If a foreign data set is damaged, CEDA cannot process the file in order to repair it. CEDA does not support update processing, which is required in order to repair a damaged data set. To repair the foreign file, you must move it back to its native environment. For information on how to repair a damaged data set, see the REPAIR statement in the DATASETS procedure in Base SAS Procedures Guide .