overviews of consistency, availability and durability
| Level | Name | Phenomena disallowed |
|---|---|---|
| PL-CS | Cursor Stability | G1, G-cursor |
| PL-2L | Monotonic View | G1, G-monotonic |
| PL-MSR | Monotonic Snapshot Reads | G1, G-MSR |
| PL-2+ | Consistent View | G1, G-single |
| PL-FCV | Forward Consistent View | G1, G-SIb |
| PL-SI | Snapshot Isolation | G1, G-SI |
| PL-2.99 | Repeatable Reads | G1, G2-item |
| PL-3U | Update Serializability | G1, G-update |
| PL-3 | Full Serializability | G1, G2 |
| Phenomenon | Description |
|---|---|
| write cycles, G0 | |
| aborted reads, G1a | |
| intermediate reads, G1b | |
| circular information flow, G1c | |
| non-atomic predicate-based reads, G1-predA | |
| non-atomic predicate-based reads w.r.t. transactions, G1-predB | |
| anti-dependency cycles, G2 | |
| item anti-dependency cycles, G2-item | |
| non-atomic SQL statements, G-SQL-atomic | |
| anti-dependency cycles at runtime, E2 | |
| single anti-dependency cycles, G-single | |
| monotonic reads, G-monotonic | |
| interference, G-SIa | |
| missed effects, G-SIb | |
| action interference, G-MSRa | |
| action missed effects, G-MSRb | |
| labeled single anti-dependency cycles, G-cursor(x) | |
| single anti-dependency cycles with update transactions, G-update | |
| single anti-dependency cycles at runtime, E-single | |
| monotonic reads at runtime, E-monotonic | |
| single anti-dependency cycles with update transactions at runtime, E-update |
| Phenomenon | Description |
|---|---|
| dirty write, P0 | |
| dirty read, P1 | |
| cursor lost update | |
| lost update, P4 | |
| non-repeatable/fuzzy read, P2 | |
| phantom, P3 | |
| read skew, A5A | |
| write skew, A5B |
source: A Critique of ANSI SQL Isolation Levels
| Phenomenon | Description |
|---|---|
| item-many-preceders, IMP | |
| predicate-many-preceders, PMP | |
| observed-transaction-vanishes, OTV | |
| non-monotonic reads, N-MR | |
| non-monotonic writes, N-MW | |
| missing read-write dependency, MRWD | |
| missing your writes, MYR | |
| lost update | |
| write skew |
source: Highly Available Transactions: Virtues and Limitations (Extended Version)