Search results
Results from the WOW.Com Content Network
Programs cannot cast directly between id and void *. [9] This includes casting between Foundation objects and Core Foundation objects. Programs must use special casts, or calls to special functions, to tell the compiler more information about an object's lifetime.
The problem that arises is that former MySQL users will create multiple databases for one project. In this context, MySQL databases are analogous in function to PostgreSQL-schemas, insomuch as PostgreSQL deliberately lacks off-the-shelf cross-database functionality (preferring multi-tenancy) that MySQL has.
Function declarations, which declare a variable and assign a function to it, are similar to variable statements, but in addition to hoisting the declaration, they also hoist the assignment – as if the entire statement appeared at the top of the containing function – and thus forward reference is also possible: the location of a function ...
Conversely, an inner join can result in disastrously slow performance or even a server crash when used in a large volume query in combination with database functions in an SQL Where clause. [2] [3] [4] A function in an SQL Where clause can result in the database ignoring relatively compact table indexes. The database may read and inner join the ...
The NEWID function in Microsoft SQL Server version 4 Transact-SQL returns standard random version-4 UUIDs, while the NEWSEQUENTIALID function returns 128-bit identifiers similar to UUIDs which are committed to ascend in sequence until the next system reboot. [33] The Oracle Database SYS_GUID function does not return a standard GUID, despite the ...
E. F. Codd mentioned nulls as a method of representing missing data in the relational model in a 1975 paper in the FDT Bulletin of ACM-SIGMOD.Codd's paper that is most commonly cited with the semantics of Null (as adopted in SQL) is his 1979 paper in the ACM Transactions on Database Systems, in which he also introduced his Relational Model/Tasmania, although much of the other proposals from ...
There is a function_exists function that determines whether a function with a given name has already been defined. Function calls must use parentheses, with the exception of zero-argument class constructor functions called with the PHP operator new , in which case parentheses are optional.
If we consider the probability function Pr[n people have at least one shared birthday], this average is determining the mean of the distribution, as opposed to the customary formulation, which asks for the median. The problem is relevant to several hashing algorithms analyzed by Donald Knuth in his book The Art of Computer Programming.