What are the implicit casting rules for promoting a data type to a List or
Map ? It seems to me the reverse mapping is more useful: casting a List
or Map to a VARCHAR is possible, so for instance I can do a join between a
Map containing {x: 1, y: 2} and a Varchar containing the exact same
string. To handle this you would add the mapping to the
ResolverTypePrecedence.secondaryImplicitCastRules.
If there is a valid promotion to List or Map in the precedenceMap, since
these are complex types I would think it belongs to the end just before the
UNION type (since Union is the superset).
On Wed, Jun 1, 2016 at 9:24 AM, Vitalii Diravka <[email protected]>
wrote:
> Hi all!
>
> I need to add List and Map data types into "precedenceMap" in the
> "ResolverTypePrecedence" class.
> And I am interested in precedence value of these data types.
> What are your thoughts about it?
>
>
> You can see all current precedence map below.
>
>
> > precedenceMap = new HashMap<MinorType, Integer>();
> > precedenceMap.put(MinorType.NULL, i += 2); // NULL is legal to
> > implicitly be promoted to any other type
> > precedenceMap.put(MinorType.FIXEDBINARY, i += 2); // Fixed-length is
> > promoted to var length
> > precedenceMap.put(MinorType.VARBINARY, i += 2);
> > precedenceMap.put(MinorType.FIXEDCHAR, i += 2);
> > precedenceMap.put(MinorType.VARCHAR, i += 2);
> > precedenceMap.put(MinorType.FIXED16CHAR, i += 2);
> > precedenceMap.put(MinorType.VAR16CHAR, i += 2);
> > precedenceMap.put(MinorType.BIT, i += 2);
> > precedenceMap.put(MinorType.TINYINT, i += 2); //type with few bytes is
> > promoted to type with more bytes ==> no data loss.
> > precedenceMap.put(MinorType.UINT1, i += 2); //signed is legal to
> > implicitly be promoted to unsigned.
> > precedenceMap.put(MinorType.SMALLINT, i += 2);
> > precedenceMap.put(MinorType.UINT2, i += 2);
> > precedenceMap.put(MinorType.INT, i += 2);
> > precedenceMap.put(MinorType.UINT4, i += 2);
> > precedenceMap.put(MinorType.BIGINT, i += 2);
> > precedenceMap.put(MinorType.UINT8, i += 2);
> > precedenceMap.put(MinorType.MONEY, i += 2);
> > precedenceMap.put(MinorType.FLOAT4, i += 2);
> > precedenceMap.put(MinorType.DECIMAL9, i += 2);
> > precedenceMap.put(MinorType.DECIMAL18, i += 2);
> > precedenceMap.put(MinorType.DECIMAL28DENSE, i += 2);
> > precedenceMap.put(MinorType.DECIMAL28SPARSE, i += 2);
> > precedenceMap.put(MinorType.DECIMAL38DENSE, i += 2);
> > precedenceMap.put(MinorType.DECIMAL38SPARSE, i += 2);
> > precedenceMap.put(MinorType.FLOAT8, i += 2);
> > precedenceMap.put(MinorType.DATE, i += 2);
> > precedenceMap.put(MinorType.TIMESTAMP, i += 2);
> > precedenceMap.put(MinorType.TIMETZ, i += 2);
> > precedenceMap.put(MinorType.TIMESTAMPTZ, i += 2);
> > precedenceMap.put(MinorType.TIME, i += 2);
> > precedenceMap.put(MinorType.INTERVALDAY, i+= 2);
> > precedenceMap.put(MinorType.INTERVALYEAR, i+= 2);
> > precedenceMap.put(MinorType.INTERVAL, i+= 2);
> > precedenceMap.put(MinorType.UNION, i += 2);
>
>
>
> Kind regards
> Vitalii
>
