![]() Once it has come up with a plan, then any tables in the FROM statement are loaded into the data engine where they can then be accessed in memory. The optimizer then intelligently strategizes how to execute the code. When a proc SQL statement is executed, the first step is the SQL optimizer scans the query inside the statement. If the DATA step is a sequential process by the record, then it is best to think of the SQL procedure as a simultaneous process for all the records. Once the buffer is filled, then the records are then populated to the output SAS data set described in the DATA statement. From here the records are then loaded sequentially into the output buffer. ![]() Once the buffer is loaded, records start to get processed in the program data vector (PDV) which is a temporary placement for the record so that any calculations can be computed. It starts out by taking records from the data source in the SET statement and loading them into the input buffer. The DATA step is a sequential process, it brings in, calculates, and outputs a single record at a time. How does SAS process data?īoth methods are ways to do to create and manipulate data, but how after decades is one not much more accepted than the other? Let’s take a look at how each one takes in and processes data: DATA Step This new enhancement to the language allowed traditional SAS programmers to continue using the DATA step while also letting programmers with a database background to easily pick up the SAS language. ![]() With the early releases of SAS 6 in the 1990s, SAS introduced the SQL procedure into the base language so that the SQL language was available as well as the DATA step for their programming. Throughout the 1980s, SQL became so popular among all relational databases that the American National Standards Institute (ANSI) developed standards so that it would remain consistent across all platforms. Meanwhile in the 1970s relational databases started taking off and the SQL language was developed by researchers at IBM as a way to program within a database. The first formal release of SAS was in 1972, which included the DATA step and a few other original procedures but not the SQL procedure. I am not sure the following code could get you what you want.History – How these processes got started in SAS If h22.check()=0 then do name1=name2 output end The following is for the first two tables. What if there are duplicated name or duplicated key ,what you gonna do ? Thank you and I appreciated the help in advance. If I didn't explain that well or if anyone has any additional questions, please feel free to reach out. I also want to not keep the 'vwx' from the 3rd table since it found a match. ![]() So in the case below, I want to keep name 'ghi' since it is in the first table, and put the key for the 2nd table in the new table on that records since the names match, and I also want to have the key for the 3rd table since the keys matched between 'ghi' in the 2nd table and 'vwx' in the 3rd table. It is also important to keep the "left-most" name. I only want to keep the names that don't have a match within any of the table combinations. I have highlighted the part I am having issues with. I have provided the code and an example of how I would like the final table to look like in the end. I am trying to merge 3 datasets together so that I only have unique records at the end.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |