Managing Processing Using PROC SQL Chapter 8 1 Imelda Go, John Grego, Jennifer Lasecki, 2011

PROC SQL OPTIONS INOBS= INOBS= –Used to restrict the number of input rows –Useful for possibly large queries (e.g., outer unions) proc sql inobs=5; select * from Ecoli outer union corr select * from Fcoli outer union corr select * from Entero; quit; 2Imelda Go, John Grego, Jennifer Lasecki, 2011

PROC SQL OPTIONS OUTOBS= OUTOBS= –Used to restrict the number of output rows –OUTOBS= by itself restores the default (all rows output) 3Imelda Go, John Grego, Jennifer Lasecki, 2011

Example: OUTOBS proc sql outobs=5; select player, atbats select player, atbats from bbstats; from bbstats;quit; playeratbats Christian Walker271 Scott Wingo240 Brady Thomas231 Evan Marzilli220 Robert Beary211 4Imelda Go, John Grego, Jennifer Lasecki, 2011

PROC SQL OPTIONS DOUBLE/NODOUBLE DOUBLE/NODOUBLE –specifies whether output is double spaced –this option does not affect the appearance of HTML output proc sql outobs=5 double; select player, atbats select player, atbats from bbstats; from bbstats;quit; 5Imelda Go, John Grego, Jennifer Lasecki, 2011

PROC SQL OPTIONS NUMBER/NONUMBER NUMBER/NONUMBER –Adds or removes row numbers from a table –The column is labeled: Row –Similar to OBS/NOOBS in PROC PRINT proc sql outobs=5 double number; select player, atbats select player, atbats from bbstats; from bbstats;quit; 6Imelda Go, John Grego, Jennifer Lasecki, 2011

PROC SQL OPTIONS  FLOW | NOFLOW FLOW=n | FLOW=n m –Controls appearance of wide character columns in listing output –n sets the width of the flowed column –Specifying n and m floats the width of the column between limits –does not affect the appearance of HTML, PDF, or RTF output 7Imelda Go, John Grego, Jennifer Lasecki, 2011

PROC SQL OPTIONS  Example of FLOW proc sql flow = double; select winner.wscore label="Matching Score", winner.date format=worddate18. label="Date", winner.wteam label="Team with Winning Score", loser.date format=worddate18. label="Date", loser.lteam label="Team with Losing Score" from secscores as winner, secscores as loser where winner.wscore=loser.lscore; quit; 8Imelda Go, John Grego, Jennifer Lasecki, 2011

PROC SQL OPTIONS  RESET can be used to change OUTOBS=, NUMBER, NODOUBLE, NOFLOW, etc  It can be inserted between SELECT clauses to restore options 9Imelda Go, John Grego, Jennifer Lasecki, 2011

PROC SQL OPTIONS  Example of RESET proc sql outobs=6 double; select player, atbats from bbstats; reset outobs= number nodouble; select player, hits from bbstats; quit; 10Imelda Go, John Grego, Jennifer Lasecki, 2011

Timing Information  When learning about indexes in Chapter 6, we used the default timing information available in the SAS Log  Timing info can be disaggregated by task using the STIMER option  Additional task info can be obtained using FULLSTIMER  Both methods are useful for benchmarking Imelda Go, John Grego, Jennifer Lasecki,

Timing Information  If CPU Time is close to Real Time, than the system is operating efficiently  In addition to Real Time and CPU Time, FULLSTIMER provides data on -Memory -Involuntary CPU time-slice releases -Page swaps Imelda Go, John Grego, Jennifer Lasecki,

Dictionaries  DICTIONARY.TABLES contains meta data about tables and views  DICTIONARY.COLUMNS contains meta data about columns in tables  Can be compared to PROC CONTENTS Imelda Go, John Grego, Jennifer Lasecki,

Dictionaries  To find what variables are available, use DESCRIBE TABLE  A specific query proc sql; select memname, memtype, nobs, nvar, num_character, num_numeric, filesize, crdate from dictionary.tables where libname='WORK'; quit; Imelda Go, John Grego, Jennifer Lasecki,