public enum Isolation extends Enum<Isolation>
Enum Constant and Description |
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READ_COMMITTED
Read Committed isolation.
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STMT_CONSISTENT_READ
Statement Consistent Read isolation.
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STMT_MONOTONIC_CONSISTENT_READ
Statement Monotonic Consistent Read isolation.
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TX_CONSISTENT_READ
Transaction Consistent Read isolation.
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TX_MONOTONIC_CONSISTENT_READ
Transaction Monotonic Consistent Read isolation.
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Modifier and Type | Method and Description |
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abstract boolean |
isConsistent()
Returns whether the isolation level guaranteed consistent reads.
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abstract boolean |
isMonotonic()
Returns whether the isolation level guarantees monotonic reads.
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String |
toString()
Return a human-readable description for this Isolation.
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static Isolation |
valueOf(String name)
Returns the enum constant of this type with the specified name.
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static Isolation[] |
values()
Returns an array containing the constants of this enum type, in the order they are declared.
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public static final Isolation READ_COMMITTED
This is the default isolation level if no level is specified. This isolation level guarantees that only committed data is visible and doesn't provide any consistency guarantees. Reads are guaranteed to be monotonic. All writes acquire a write lock and reads do not acquire any lock. Any attempt to write to a locked entry will result in an exception; the request will not block. This is the weakest of the isolation levels and will generally be the most performant at the cost of read consistency.
public static final Isolation STMT_CONSISTENT_READ
Provides statement scoped read consistency. This isolation level guarantees that all the data read by a single operation comes from a single point in time; the time that the statement began execution. Reads are not guaranteed to be monotonic. All writes acquire a write lock and reads do not acquire any lock. Any attempt to write to a locked entry will result in an exception; the request will not block.
public static final Isolation TX_CONSISTENT_READ
Provides transaction scoped read consistency. This isolation level guarantees that all the data read in a transaction comes from a single point in time; the time that the transaction began. Reads are not guaranteed to be monotonic. All writes acquire a write lock and reads do not acquire any lock. Any attempt to write to a locked entry will result in an exception; the request will not block.
Read operations with this isolation level may produce a VersionNotAvailableException
if attempting to read a historical version of the data that is no longer available in storage.
public static final Isolation STMT_MONOTONIC_CONSISTENT_READ
Provides statement scoped read consistency and monotonic reads. This isolation level guarantees that all data read by a single operation comes from a single point in time; the time that the statement began execution. Reads are guaranteed to be monotonic. This means that a read is guaranteed to return a version that is equal to or greater than any version that was previously encountered while using the connection. Due to the monotinic read guarantee, reads with this isolation may block until the necessary versions are available. All writes acquire a write lock and reads do not acquire any lock. Any attempt to write to a locked entry will result in an exception; the request will not block waiting for a write lock.
public static final Isolation TX_MONOTONIC_CONSISTENT_READ
Provides transaction scoped read consistency and monotonic reads. This isolation level guarantees that all data read by a single operation comes from a single point in time; the time that the transaction began. Reads are guaranteed to be monotonic. This means that a read is guaranteed to return a version that is equal to or greater than any version that was previously encountered while using the connection. Due to the monotinic read guarantee, the initial read in a transaction with this isolation may block until the necessary versions are available. All writes acquire a write lock and reads do not acquire any lock. Any attempt to write to a locked entry will result in an exception; the request will not block waiting for a write lock.
Read operations with this isolation level may produce a VersionNotAvailableException
if attempting to read a historical version of the data that is no longer available in storage.
public static Isolation[] values()
for (Isolation c : Isolation.values()) System.out.println(c);
public static Isolation valueOf(String name)
name
- the name of the enum constant to be returned.IllegalArgumentException
- if this enum type has no constant with the specified nameNullPointerException
- if the argument is nullpublic abstract boolean isConsistent()
public abstract boolean isMonotonic()