space ID sparse file spin Spring SQL  An identifier used to uniquely identify an  InnoDB tablespace  within a MySQL instance. The space ID for the system tablespace  is always zero; this same ID applies to all tables within the system tablespace or within a general tablespace. Each  file-per-table  tablespace and  general tablespace  has its own space ID.  A Java-based application framework designed for assisting in application design by providing a way to configure components. Prior to MySQL 5.6, this hardcoded value presented difficulties in moving  InnoDB  tablespace files between MySQL instances. Starting in MySQL 5.6, you can copy tablespace files between instances by using the transportable tablespace  feature involving the statements  FLUSH TABLES ... FOR EXPORT ,  ALTER TABLE ... DISCARD TABLESPACE , and  ALTER TABLE ... IMPORT TABLESPACE . The information needed to adjust the space ID is conveyed in the  .cfg file  which you copy along with the tablespace. See Section 15.6.1.3, “Importing InnoDB Tables”  for details. See Also .cfg file, file-per-table, general tablespace, .ibd file, system tablespace, tablespace, transportable tablespace.  A type of file that uses file system space more efficiently by writing metadata representing empty blocks to disk instead of writing the actual empty space. The  InnoDB transparent page compression  feature relies on sparse file support. For more information, see Section 15.9.2, “InnoDB Page Compression” . See Also hole punching, transparent page compression.  A type of  wait  operation that continuously tests whether a resource becomes available. This technique is used for resources that are typically held only for brief periods, where it is more efficient to wait in a “busy loop”  than to put the thread to sleep and perform a context switch. If the resource does not become available within a short time, the spin loop ceases and another wait technique is used. See Also latch, lock, mutex, wait. See Also J2EE.  The Structured Query Language that is standard for performing database operations. Often divided into the categories  DDL ,  DML , and  queries . MySQL includes some additional statement categories such as  replication . See Chapter 9,  Language Structure  for the building blocks of SQL syntax, Chapter 11,  Data Types  for the data types to use for MySQL table columns, Chapter 13,  SQL Statements  for details about SQL statements and their associated categories, and Chapter 12,  Functions and Operators  for standard and MySQL-specific functions to use in queries. See Also DDL, DML, query, replication.  An error code defined by the  JDBC  standard, for exception handling by applications using  Connector/J . See Also Connector/J, JDBC.  Acronym for “solid-state drive” . A type of storage device with different performance characteristics than a traditional hard disk drive ( HDD ): smaller storage capacity, faster for random reads, no moving parts, and with a number of considerations affecting write performance. Its performance characteristics can influence the throughput of a  disk-bound  workload. See Also disk-bound, HDD.  Acronym for “secure sockets layer” . Provides the encryption layer for network communication between an application and a MySQL database server. 6188 SSL SSD SQLState