Roberto Thanks for the experiment. Originally MAL was designed to allow for such actions, and since recent changes, has become easier. The ratio was to easily take snippets of a SQL query (including some wrapped up catalog stuff) and turn it into more controllable MAL tests. Consider it a bug when you cannot do what you did. We'll fix it in due time. regards, Martin On 10/10/16 15:12, Roberto Cornacchia wrote:
Almost for fun, I did this little experiment: take the output of an EXPLAIN from sql, and execute it in MAL (mclient -l mal).
I found only *1* detail which doesn't parse, here it is in a minimal example:
* Got the explain of a trivial query:
sql>\f raw sql>explain select name from sys.functions; % .explain # table_name % mal # name % clob # type % 94 # length function user.s4_1():void; X_32:void := querylog.define("explain select name from sys.functions;","default_pipe",21); X_16 := bat.new(nil:oid,nil:str); X_24 := bat.append(X_16,"sys.functions"); X_19 := bat.new(nil:oid,nil:str); X_26 := bat.append(X_19,"name"); X_20 := bat.new(nil:oid,nil:str); X_27 := bat.append(X_20,"varchar"); X_21 := bat.new(nil:oid,nil:int); X_29 := bat.append(X_21,256); X_23 := bat.new(nil:oid,nil:int); X_31 := bat.append(X_23,0); X_1 := sql.mvc(); C_2:bat[:oid] := sql.tid(X_1,"sys","functions"); X_5:bat[:str] := sql.bind(X_1,"sys","functions","name",0); (C_8,r1_8) := sql.bind(X_1,"sys","functions","name",2); X_11:bat[:str] := sql.bind(X_1,"sys","functions","name",1); X_13 := sql.delta(X_5,C_8,r1_8,X_11); X_14 := algebra.projection(C_2,X_13); sql.resultSet(X_24,X_26,X_27,X_29,X_31,X_14); end user.s4_1; # optimizer.mitosis() # optimizer.dataflow()
* Opened a MAL session, initialized sql, and pasted the function above:
mal>sql.init(); mal>function user.s4_1():void; mal> X_32:void := querylog.define("explain select name from sys.functions;","default_pipe",21); mal> X_16 := bat.new(nil:oid,nil:str); mal> X_24 := bat.append(X_16,"sys.functions"); mal> X_19 := bat.new(nil:oid,nil:str); mal> X_26 := bat.append(X_19,"name"); mal> X_20 := bat.new(nil:oid,nil:str); mal> X_27 := bat.append(X_20,"varchar"); mal> X_21 := bat.new(nil:oid,nil:int); mal> X_29 := bat.append(X_21,256); mal> X_23 := bat.new(nil:oid,nil:int); mal> X_31 := bat.append(X_23,0); mal> X_1 := sql.mvc(); mal> C_2:bat[:oid] := sql.tid(X_1,"sys","functions"); mal> X_5:bat[:str] := sql.bind(X_1,"sys","functions","name",0); mal> (C_8,*r1_8*) := sql.bind(X_1,"sys","functions","name",2); mal> X_11:bat[:str] := sql.bind(X_1,"sys","functions","name",1); mal> X_13 := sql.delta(X_5,C_8,r1_8,X_11); mal> X_14 := algebra.projection(C_2,X_13); mal> sql.resultSet(X_24,X_26,X_27,X_29,X_31,X_14); mal>end user.s4_1; MAPI = (monetdb) /tmp/.s.monetdb.54500 QUERY = end user.s4_1; ERROR = !TypeException:user.s4_1[17]:'sql.delta' undefined in: X_13:any := sql.delta(X_5:bat[:str],C_8:bat[:oid],*r1_8:bat[:any]*,X_11:bat[:str]); mal>
The error is easy to find: sql.delta() expects r1_8 to be of type :bat[:str], but it gets :bat[:any] instead.
* If I fix it manually:
mal>function user.s4_1():void; mal> X_32:void := querylog.define("explain select name from sys.functions;","default_pipe",21); mal> X_16 := bat.new(nil:oid,nil:str); mal> X_24 := bat.append(X_16,"sys.functions"); mal> X_19 := bat.new(nil:oid,nil:str); mal> X_26 := bat.append(X_19,"name"); mal> X_20 := bat.new(nil:oid,nil:str); mal> X_27 := bat.append(X_20,"varchar"); mal> X_21 := bat.new(nil:oid,nil:int); mal> X_29 := bat.append(X_21,256); mal> X_23 := bat.new(nil:oid,nil:int); mal> X_31 := bat.append(X_23,0); mal> X_1 := sql.mvc(); mal> C_2:bat[:oid] := sql.tid(X_1,"sys","functions"); mal> X_5:bat[:str] := sql.bind(X_1,"sys","functions","name",0); mal> (C_8,*r1_8:bat[:str]*) := sql.bind(X_1,"sys","functions","name",2); mal> X_11:bat[:str] := sql.bind(X_1,"sys","functions","name",1); mal> X_13 := sql.delta(X_5,C_8,r1_8,X_11); mal> X_14 := algebra.projection(C_2,X_13); mal> sql.resultSet(X_24,X_26,X_27,X_29,X_31,X_14); mal>end user.s4_1; mal>
Yay, it works.
** The reason I write this email:* - I suspect that the output of EXPLAIN is not meant to necessarily be re-parsable, but just to be informative - Nevertheless, it really is almost re-parsable. I tried a much larger query, (2000+ lines of MAL), and this was the only detail. It looks like fixing that small detail could be worth it. - Also, I wonder if this is, in fact, a bug. Binds to access types 0 and 1 do get the right type information. Why not access type 2?
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