[web2py] How to use the new cache-options for referenced table by IS_IN_DB ?

[Omi Chiba]

I want to speed up to pull the referenced table by IS_IN_DB. 

For example, EDXUSF00 is referencing TDMUSJ00 table which takes 10 seconds 
to display the form because it has about 40,000 records. I was wondring if 
I can cache TDMUSJ00 so that it will be faster when the form is displayed 
second time.


db.define_table('TDMUSJ00',
    Field('TRTRCD', length=8, label="End User Code"),
    Field('TRTSCD', length=3, label="Dept"),
    Field('TRTRKN', length=30, label="Cust Name"),
    primarykey=['TRTRCD'])

db.define_table('EDXUSF00',
    Field('USDIID', length=5,  label="Dist Code"),
    Field('USACCT', length=30,  label="Dist End User Code"),
    Field('USUSCD', length=8,  label="End User Code"),
    Field('USUPFL', length=1,  label="OZ UPLOAD FLAG"),
    Field('USCRBY', length=20, default = auth.user.username.upper() if 
auth.user else None, label="Created by"),
    Field('USCRDT', 'datetime', default =request.now, label="Created on"), 
   
    Field('USUPBY', length=20, update = auth.user.username.upper() if 
auth.user else None, label="Updated by"),
    Field('USUPDT', 'datetime', update =request.now, label="Updated on"),  
    primarykey=['USDIID', 'USACCT'])

db.EDXUSF00.USDIID.requires=IS_IN_DB(db,db.EDMFVF00.FVTKCD,'%(FVNAME)s 
(%(FVTKCD)s)')
db.EDXUSF00.USACCT.requires=[IS_NOT_EMPTY(),IS_LENGTH(30,1),IS_UPPER()]
db.EDXUSF00.USUSCD.requires=IS_IN_DB(db,db.TDMUSJ00.TRTRCD,'%(TRTRKN)s 
(%(TRTRCD)s)')
db.EDXUSF00.USUPFL.writable = db.EDXUSF00.USUPFL.readable = False
db.EDXUSF00.USCRBY.writable = False
db.EDXUSF00.USCRDT.writable = False
db.EDXUSF00.USUPBY.writable = False
db.EDXUSF00.USUPDT.writable = False

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