Query based insertion or updating of blob values
On the other hand, it has a much smaller range of allowable values, and sometimes its special capabilities can be a handicap. My SQL supports many aliases for compatibility, such as can store values ranging from 0 to 255 instead of from −128 to 127.Signed and unsigned types use the same amount of storage space and have the same performance, so use whatever’s best for your data range. This is meaningless for most applications: it does not restrict the legal range of values, but simply specifies the number of characters My SQL’s interactive tools (such as the command-line client) will reserve for display purposes.You need to understand the whole system to understand how each piece will affect others.You might find it useful to review this chapter after reading the chapters on indexing and query optimization.
It’s a chapter on My SQL database design—it’s about what is different when designing databases with My SQL rather than other relational database management systems.
In these three chapters, we will explore the interaction of logical design, physical design, and query execution.
This requires a big-picture approach as well as attention to details.
A number in My SQL 5.0 and newer can have up to 65 digits.
Earlier My SQL versions had a limit of 254 digits and stored the values as unpacked strings (one byte per digit).
Both floating-point and column, you can specify the maximum allowed digits before and after the decimal point. My SQL 5.0 and newer pack the digits into a binary string (nine digits per four bytes).