@@ -8078,78 +8078,84 @@ In-memory indexes are automatically used for in-memory databases, but can also b
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@@ -8078,78 +8078,84 @@ In-memory indexes are automatically used for in-memory databases, but can also b
In-memory hash indexes are backed by a hash table and are usually faster than regular indexes. However, hash indexes only supports direct lookup (<code>WHERE ID = ?</code>) but not range scan (<code>WHERE ID < ?</code>). To use hash indexes, use HASH as in: <code>CREATE UNIQUE HASH INDEX</code> and <code>CREATE TABLE ...(ID INT PRIMARY KEY HASH,...)</code>.
In-memory hash indexes are backed by a hash table and are usually faster than regular indexes. However, hash indexes only supports direct lookup (<code>WHERE ID = ?</code>) but not range scan (<code>WHERE ID < ?</code>). To use hash indexes, use HASH as in: <code>CREATE UNIQUE HASH INDEX</code> and <code>CREATE TABLE ...(ID INT PRIMARY KEY HASH,...)</code>.
@performance_1429_h3
@performance_1429_h3
Optimization Examples
Use Prepared Statements
@performance_1430_p
@performance_1430_p
See <code>src/test/org/h2/samples/optimizations.sql</code> for a few examples of queries that benefit from special optimizations built into the database.
If possible, use prepared statements with parameters. Avoid generating SQL statements with a variable size IN(...) list. Instead, use arrays as in the following example:
@performance_1431_h3
@performance_1431_h3
Cache Size and Type
Optimization Examples
@performance_1432_p
@performance_1432_p
By default the cache size of H2 is quite small. Consider using a larger cache size, or enable the second level soft reference cache. See also <a href="features.html#cache_settings">Cache Settings</a>.
See <code>src/test/org/h2/samples/optimizations.sql</code> for a few examples of queries that benefit from special optimizations built into the database.
@performance_1433_h3
@performance_1433_h3
Data Types
Cache Size and Type
@performance_1434_p
@performance_1434_p
By default the cache size of H2 is quite small. Consider using a larger cache size, or enable the second level soft reference cache. See also <a href="features.html#cache_settings">Cache Settings</a>.
@performance_1435_h3
Data Types
@performance_1436_p
Each data type has different storage and performance characteristics:
Each data type has different storage and performance characteristics:
@performance_1435_li
@performance_1437_li
The <code>DECIMAL/NUMERIC</code> type is slower and requires more storage than the <code>REAL</code> and <code>DOUBLE</code> types.
The <code>DECIMAL/NUMERIC</code> type is slower and requires more storage than the <code>REAL</code> and <code>DOUBLE</code> types.
@performance_1436_li
@performance_1438_li
Text types are slower to read, write, and compare than numeric types and generally require more storage.
Text types are slower to read, write, and compare than numeric types and generally require more storage.
@performance_1437_li
@performance_1439_li
See <a href="advanced.html#large_objects">Large Objects</a> for information on <code>BINARY</code> vs. <code>BLOB</code> and <code>VARCHAR</code> vs. <code>CLOB</code> performance.
See <a href="advanced.html#large_objects">Large Objects</a> for information on <code>BINARY</code> vs. <code>BLOB</code> and <code>VARCHAR</code> vs. <code>CLOB</code> performance.
@performance_1438_li
@performance_1440_li
Parsing and formatting takes longer for the <code>TIME</code>, <code>DATE</code>, and <code>TIMESTAMP</code> types than the numeric types.
Parsing and formatting takes longer for the <code>TIME</code>, <code>DATE</code>, and <code>TIMESTAMP</code> types than the numeric types.
@performance_1439_code
@performance_1441_code
SMALLINT/TINYINT/BOOLEAN
SMALLINT/TINYINT/BOOLEAN
@performance_1440_li
@performance_1442_li
are not significantly smaller or faster to work with than <code>INTEGER</code> in most modes.
are not significantly smaller or faster to work with than <code>INTEGER</code> in most modes.
@performance_1441_h3
@performance_1443_h3
Sorted Insert Optimization
Sorted Insert Optimization
@performance_1442_p
@performance_1444_p
To reduce disk space usage and speed up table creation, an optimization for sorted inserts is available. When used, b-tree pages are split at the insertion point. To use this optimization, add <code>SORTED</code> before the <code>SELECT</code> statement:
To reduce disk space usage and speed up table creation, an optimization for sorted inserts is available. When used, b-tree pages are split at the insertion point. To use this optimization, add <code>SORTED</code> before the <code>SELECT</code> statement:
@performance_1443_h2
@performance_1445_h2
Using the Built-In Profiler
Using the Built-In Profiler
@performance_1444_p
@performance_1446_p
A very simple Java profiler is built-in. To use it, use the following template:
A very simple Java profiler is built-in. To use it, use the following template:
@performance_1445_h2
@performance_1447_h2
Fast Database Import
Fast Database Import
@performance_1446_p
@performance_1448_p
To speed up large imports, consider using the following options temporarily:
To speed up large imports, consider using the following options temporarily:
@performance_1447_code
@performance_1449_code
SET CACHE_SIZE
SET CACHE_SIZE
@performance_1448_li
@performance_1450_li
(a large cache is faster)
(a large cache is faster)
@performance_1449_code
@performance_1451_code
SET LOCK_MODE 0
SET LOCK_MODE 0
@performance_1450_li
@performance_1452_li
(disable locking)
(disable locking)
@performance_1451_code
@performance_1453_code
SET UNDO_LOG 0
SET UNDO_LOG 0
@performance_1452_li
@performance_1454_li
(disable the session undo log)
(disable the session undo log)
@performance_1453_p
@performance_1455_p
These options can be set in the database URL: <code>jdbc:h2:~/test;CACHE_SIZE=65536;LOCK_MODE=0;UNDO_LOG=0</code>. Most of those options are not recommended for regular use, that means you need to reset them after use.
These options can be set in the database URL: <code>jdbc:h2:~/test;CACHE_SIZE=65536;LOCK_MODE=0;UNDO_LOG=0</code>. Most of those options are not recommended for regular use, that means you need to reset them after use.
# In-memory hash indexes are backed by a hash table and are usually faster than regular indexes. However, hash indexes only supports direct lookup (<code>WHERE ID = ?</code>) but not range scan (<code>WHERE ID < ?</code>). To use hash indexes, use HASH as in: <code>CREATE UNIQUE HASH INDEX</code> and <code>CREATE TABLE ...(ID INT PRIMARY KEY HASH,...)</code>.
# In-memory hash indexes are backed by a hash table and are usually faster than regular indexes. However, hash indexes only supports direct lookup (<code>WHERE ID = ?</code>) but not range scan (<code>WHERE ID < ?</code>). To use hash indexes, use HASH as in: <code>CREATE UNIQUE HASH INDEX</code> and <code>CREATE TABLE ...(ID INT PRIMARY KEY HASH,...)</code>.
@performance_1429_h3
@performance_1429_h3
#Optimization Examples
#Use Prepared Statements
@performance_1430_p
@performance_1430_p
# See <code>src/test/org/h2/samples/optimizations.sql</code> for a few examples of queries that benefit from special optimizations built into the database.
# If possible, use prepared statements with parameters. Avoid generating SQL statements with a variable size IN(...) list. Instead, use arrays as in the following example:
@performance_1431_h3
@performance_1431_h3
#Cache Size and Type
#Optimization Examples
@performance_1432_p
@performance_1432_p
# By default the cache size of H2 is quite small. Consider using a larger cache size, or enable the second level soft reference cache. See also <a href="features.html#cache_settings">Cache Settings</a>.
# See <code>src/test/org/h2/samples/optimizations.sql</code> for a few examples of queries that benefit from special optimizations built into the database.
@performance_1433_h3
@performance_1433_h3
データ型
#Cache Size and Type #データ型
@performance_1434_p
@performance_1434_p
# By default the cache size of H2 is quite small. Consider using a larger cache size, or enable the second level soft reference cache. See also <a href="features.html#cache_settings">Cache Settings</a>.
@performance_1435_h3
データ型
@performance_1436_p
# Each data type has different storage and performance characteristics:
# Each data type has different storage and performance characteristics:
@performance_1435_li
@performance_1437_li
#The <code>DECIMAL/NUMERIC</code> type is slower and requires more storage than the <code>REAL</code> and <code>DOUBLE</code> types.
#The <code>DECIMAL/NUMERIC</code> type is slower and requires more storage than the <code>REAL</code> and <code>DOUBLE</code> types.
@performance_1436_li
@performance_1438_li
#Text types are slower to read, write, and compare than numeric types and generally require more storage.
#Text types are slower to read, write, and compare than numeric types and generally require more storage.
@performance_1437_li
@performance_1439_li
#See <a href="advanced.html#large_objects">Large Objects</a> for information on <code>BINARY</code> vs. <code>BLOB</code> and <code>VARCHAR</code> vs. <code>CLOB</code> performance.
#See <a href="advanced.html#large_objects">Large Objects</a> for information on <code>BINARY</code> vs. <code>BLOB</code> and <code>VARCHAR</code> vs. <code>CLOB</code> performance.
@performance_1438_li
@performance_1440_li
#Parsing and formatting takes longer for the <code>TIME</code>, <code>DATE</code>, and <code>TIMESTAMP</code> types than the numeric types.
#Parsing and formatting takes longer for the <code>TIME</code>, <code>DATE</code>, and <code>TIMESTAMP</code> types than the numeric types.
@performance_1439_code
@performance_1441_code
#SMALLINT/TINYINT/BOOLEAN
#SMALLINT/TINYINT/BOOLEAN
@performance_1440_li
@performance_1442_li
# are not significantly smaller or faster to work with than <code>INTEGER</code> in most modes.
# are not significantly smaller or faster to work with than <code>INTEGER</code> in most modes.
@performance_1441_h3
@performance_1443_h3
#Sorted Insert Optimization
#Sorted Insert Optimization
@performance_1442_p
@performance_1444_p
# To reduce disk space usage and speed up table creation, an optimization for sorted inserts is available. When used, b-tree pages are split at the insertion point. To use this optimization, add <code>SORTED</code> before the <code>SELECT</code> statement:
# To reduce disk space usage and speed up table creation, an optimization for sorted inserts is available. When used, b-tree pages are split at the insertion point. To use this optimization, add <code>SORTED</code> before the <code>SELECT</code> statement:
@performance_1443_h2
@performance_1445_h2
#Using the Built-In Profiler
#Using the Built-In Profiler
@performance_1444_p
@performance_1446_p
# A very simple Java profiler is built-in. To use it, use the following template:
# A very simple Java profiler is built-in. To use it, use the following template:
@performance_1445_h2
@performance_1447_h2
#Fast Database Import
#Fast Database Import
@performance_1446_p
@performance_1448_p
# To speed up large imports, consider using the following options temporarily:
# To speed up large imports, consider using the following options temporarily:
@performance_1447_code
@performance_1449_code
#SET CACHE_SIZE
#SET CACHE_SIZE
@performance_1448_li
@performance_1450_li
# (a large cache is faster)
# (a large cache is faster)
@performance_1449_code
@performance_1451_code
#SET LOCK_MODE 0
#SET LOCK_MODE 0
@performance_1450_li
@performance_1452_li
# (disable locking)
# (disable locking)
@performance_1451_code
@performance_1453_code
#SET UNDO_LOG 0
#SET UNDO_LOG 0
@performance_1452_li
@performance_1454_li
# (disable the session undo log)
# (disable the session undo log)
@performance_1453_p
@performance_1455_p
# These options can be set in the database URL: <code>jdbc:h2:~/test;CACHE_SIZE=65536;LOCK_MODE=0;UNDO_LOG=0</code>. Most of those options are not recommended for regular use, that means you need to reset them after use.
# These options can be set in the database URL: <code>jdbc:h2:~/test;CACHE_SIZE=65536;LOCK_MODE=0;UNDO_LOG=0</code>. Most of those options are not recommended for regular use, that means you need to reset them after use.
performance_1426_p=\ Using in-memory indexes, specially in-memory hash indexes, can speed up queries and data manipulation.
performance_1426_p=\ Using in-memory indexes, specially in-memory hash indexes, can speed up queries and data manipulation.
performance_1427_p=In-memory indexes are automatically used for in-memory databases, but can also be created for persistent databases using <code>CREATE MEMORY TABLE</code>. In many cases, the rows itself will also be kept in-memory. Please note this may cause memory problems for large tables.
performance_1427_p=In-memory indexes are automatically used for in-memory databases, but can also be created for persistent databases using <code>CREATE MEMORY TABLE</code>. In many cases, the rows itself will also be kept in-memory. Please note this may cause memory problems for large tables.
performance_1428_p=\ In-memory hash indexes are backed by a hash table and are usually faster than regular indexes. However, hash indexes only supports direct lookup (<code>WHERE ID \=?</code>) but not range scan (<code>WHERE ID < ?</code>). To use hash indexes, use HASH as in\:<code>CREATE UNIQUE HASH INDEX</code> and <code>CREATE TABLE ...(ID INT PRIMARY KEY HASH,...)</code>.
performance_1428_p=\ In-memory hash indexes are backed by a hash table and are usually faster than regular indexes. However, hash indexes only supports direct lookup (<code>WHERE ID \=?</code>) but not range scan (<code>WHERE ID < ?</code>). To use hash indexes, use HASH as in\:<code>CREATE UNIQUE HASH INDEX</code> and <code>CREATE TABLE ...(ID INT PRIMARY KEY HASH,...)</code>.
performance_1429_h3=Optimization Examples
performance_1429_h3=Use Prepared Statements
performance_1430_p=\ See <code>src/test/org/h2/samples/optimizations.sql</code> for a few examples of queries that benefit from special optimizations built into the database.
performance_1430_p=\ If possible, use prepared statements with parameters. Avoid generating SQL statements with a variable size IN(...) list. Instead, use arrays as in the following example\:
performance_1431_h3=Cache Size and Type
performance_1431_h3=Optimization Examples
performance_1432_p=\ By default the cache size of H2 is quite small. Consider using a larger cache size, or enable the second level soft reference cache. See also <a href\="features.html\#cache_settings">Cache Settings</a>.
performance_1432_p=\ See <code>src/test/org/h2/samples/optimizations.sql</code> for a few examples of queries that benefit from special optimizations built into the database.
performance_1433_h3=Data Types
performance_1433_h3=Cache Size and Type
performance_1434_p=\ Each data type has different storage and performance characteristics\:
performance_1434_p=\ By default the cache size of H2 is quite small. Consider using a larger cache size, or enable the second level soft reference cache. See also <a href\="features.html\#cache_settings">Cache Settings</a>.
performance_1435_li=The <code>DECIMAL/NUMERIC</code> type is slower and requires more storage than the <code>REAL</code> and <code>DOUBLE</code> types.
performance_1435_h3=Data Types
performance_1436_li=Text types are slower to read, write, and compare than numeric types and generally require more storage.
performance_1436_p=\ Each data type has different storage and performance characteristics\:
performance_1437_li=See <a href\="advanced.html\#large_objects">Large Objects</a> for information on <code>BINARY</code> vs. <code>BLOB</code> and <code>VARCHAR</code> vs. <code>CLOB</code> performance.
performance_1437_li=The <code>DECIMAL/NUMERIC</code> type is slower and requires more storage than the <code>REAL</code> and <code>DOUBLE</code> types.
performance_1438_li=Parsing and formatting takes longer for the <code>TIME</code>, <code>DATE</code>, and <code>TIMESTAMP</code> types than the numeric types.
performance_1438_li=Text types are slower to read, write, and compare than numeric types and generally require more storage.
performance_1439_code=SMALLINT/TINYINT/BOOLEAN
performance_1439_li=See <a href\="advanced.html\#large_objects">Large Objects</a> for information on <code>BINARY</code> vs. <code>BLOB</code> and <code>VARCHAR</code> vs. <code>CLOB</code> performance.
performance_1440_li=\ are not significantly smaller or faster to work with than <code>INTEGER</code> in most modes.
performance_1440_li=Parsing and formatting takes longer for the <code>TIME</code>, <code>DATE</code>, and <code>TIMESTAMP</code> types than the numeric types.
performance_1441_h3=Sorted Insert Optimization
performance_1441_code=SMALLINT/TINYINT/BOOLEAN
performance_1442_p=\ To reduce disk space usage and speed up table creation, an optimization for sorted inserts is available. When used, b-tree pages are split at the insertion point. To use this optimization, add <code>SORTED</code> before the <code>SELECT</code> statement\:
performance_1442_li=\ are not significantly smaller or faster to work with than <code>INTEGER</code> in most modes.
performance_1443_h2=Using the Built-In Profiler
performance_1443_h3=Sorted Insert Optimization
performance_1444_p=\ A very simple Java profiler is built-in. To use it, use the following template\:
performance_1444_p=\ To reduce disk space usage and speed up table creation, an optimization for sorted inserts is available. When used, b-tree pages are split at the insertion point. To use this optimization, add <code>SORTED</code> before the <code>SELECT</code> statement\:
performance_1445_h2=Fast Database Import
performance_1445_h2=Using the Built-In Profiler
performance_1446_p=\ To speed up large imports, consider using the following options temporarily\:
performance_1446_p=\ A very simple Java profiler is built-in. To use it, use the following template\:
performance_1447_code=SET CACHE_SIZE
performance_1447_h2=Fast Database Import
performance_1448_li=\ (a large cache is faster)
performance_1448_p=\ To speed up large imports, consider using the following options temporarily\:
performance_1449_code=SET LOCK_MODE 0
performance_1449_code=SET CACHE_SIZE
performance_1450_li=\ (disable locking)
performance_1450_li=\ (a large cache is faster)
performance_1451_code=SET UNDO_LOG 0
performance_1451_code=SET LOCK_MODE 0
performance_1452_li=\ (disable the session undo log)
performance_1452_li=\ (disable locking)
performance_1453_p=\ These options can be set in the database URL\:<code>jdbc\:h2\:~/test;CACHE_SIZE\=65536;LOCK_MODE\=0;UNDO_LOG\=0</code>. Most of those options are not recommended for regular use, that means you need to reset them after use.
performance_1453_code=SET UNDO_LOG 0
performance_1454_li=\ (disable the session undo log)
performance_1455_p=\ These options can be set in the database URL\:<code>jdbc\:h2\:~/test;CACHE_SIZE\=65536;LOCK_MODE\=0;UNDO_LOG\=0</code>. Most of those options are not recommended for regular use, that means you need to reset them after use.
quickstart_1000_h1=Quickstart
quickstart_1000_h1=Quickstart
quickstart_1001_a=\ Embedding H2 in an Application
quickstart_1001_a=\ Embedding H2 in an Application
