Currently, the PRUNE MATERIALIZED VIEW statement performs all its
reads and writes in a single, continous sequence. This takes too
much time even for a moderate amount of 'PRUNED' data.
Instead, we want to make it possible to set a concurrency of the
reads and writes performed while processing the PRUNE statement,
so that if the user so desires, it may finish the PRUNING quicker
at the cost of adding more load on the cluster.
In this patch we add the CONCURRENCY setting to the USING clause
in cql. In the next patch, we'll be using it to actually set the
concurrency of PRUNE MATERIALIZED VIEW.
Our documentation states that writing an item with "USING TTL 0" means it
should never expire. This should be true even if the table has a default
TTL. But Scylla mistakenly handled "USING TTL 0" exactly like having no
USING TTL at all (i.e., it took the default TTL, instead of unlimited).
We had two xfailing tests demonstrating that Scylla's behavior in this
is different from Cassandra. Scylla's behavior in this case was also
undocumented.
By the way, Cassandra used to have the same bug (CASSANDRA-11207) but
it was fixed already in 2016 (Cassandra 3.6).
So in this patch we fix Scylla's "USING TTL 0" behavior to match the
documentation and Cassandra's behavior since 2016. One xfailing test
starts to pass and the second test passes this bug and fails on a
different one. This patch also adds a third test for "USING TTL ?"
with UNSET_VALUE - it behaves, on both Scylla and Cassandra, like a
missing "USING TTL".
The origin of this bug was that after parsing the statement, we saved
the USING TTL in an integer, and used 0 for the case of no USING TTL
given. This meant that we couldn't tell if we have USING TTL 0 or
no USING TTL at all. This patch uses an std::optional so we can tell
the case of a missing USING TTL from the case of USING TTL 0.
Fixes#6447
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closes#13079
The CQL binary protocol introduced "unset" values in version 4
of the protocol. Unset values can be bound to variables, which
cause certain CQL fragments to be skipped. For example, the
fragment `SET a = :var` will not change the value of `a` if `:var`
is bound to an unset value.
Unsets, however, are very limited in where they can appear. They
can only appear at the top-level of an expression, and any computation
done with them is invalid. For example, `SET list_column = [3, :var]`
is invalid if `:var` is bound to unset.
This causes the code to be littered with checks for unset, and there
are plenty of tests dedicated to catching unsets. However, a simpler
way is possible - prevent the infiltration of unsets at the point of
entry (when evaluating a bind variable expression), and introduce
guards to check for the few cases where unsets are allowed.
This is what this long patch does. It performs the following:
(general)
1. unset is removed from the possible values of cql3::raw_value and
cql3::raw_value_view.
(external->cql3)
2. query_options is fortified with a vector of booleans,
unset_bind_variable_vector, where each boolean corresponds to a bind
variable index and is true when it is unset.
3. To avoid churn, two compatiblity structs are introduced:
cql3::raw_value{,_view}_vector_with_unset, which can be constructed
from a std::vector<raw_value{,_view/}>, which is what most callers
have. They can also be constructed with explicit unset vectors, for
the few cases they are needed.
(cql3->variables)
4. query_options::get_value_at() now throws if the requested bind variable
is unset. This replaces all the throwing checks in expression evaluation
and statement execution, which are removed.
5. A new query_options::is_unset() is added for the users that can tolerate
unset; though it is not used directly.
6. A new cql3::unset_operation_guard class guards against unsets. It accepts
an expression, and can be queried whether an unset is present. Two
conditions are checked: the expression must be a singleton bind
variable, and at runtime it must be bound to an unset value.
7. The modification_statement operations are split into two, via two
new subclasses of cql3::operation. cql3::operation_no_unset_support
ignores unsets completely. cql3::operation_skip_if_unset checks if
an operand is unset (luckily all operations have at most one operand that
tolerates unset) and applies unset_operation_guard to it.
8. The various sites that accept expressions or operations are modified
to check for should_skip_operation(). This are the loops around
operations in update_statement and delete_statement, and the checks
for unset in attributes (LIMIT and PER PARTITION LIMIT)
(tests)
9. Many unset tests are removed. It's now impossible to enter an
unset value into the expression evaluation machinery (there's
just no unset value), so it's impossible to test for it.
10. Other unset tests now have to be invoked via bind variables,
since there's no way to create an unset cql3::expr::constant.
11. Many tests have their exception message match strings relaxed.
Since unsets are now checked very early, we don't know the context
where they happen. It would be possible to reintroduce it (by adding
a format string parameter to cql3::unset_operation_guard), but it
seems not to be worth the effort. Usage of unsets is rare, and it is
explicit (at least with the Python driver, an unset cannot be
introduced by ommission).
I tried as an alternative to wrap cql3::raw_value{,_view} (that doesn't
recognize unsets) with cql3::maybe_unset_value (that does), but that
caused huge amounts of churn, so I abandoned that in favor of the
current approach.
Closes#12517
After fcb8d040 ("treewide: use Software Package Data Exchange
(SPDX) license identifiers"), many dual-licensed files were
left with empty comments on top. Remove them to avoid visual
noise.
Closes#10562
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
Stop using database (and including database.hh) for schema related
purposes and use data_dictionary instead.
data_dictionary::database::real_database() is called from several
places, for these reasons:
- calling yet-to-be-converted code
- callers with a legitimate need to access data (e.g. system_keyspace)
but with the ::database accessor removed from query_processor.
We'll need to find another way to supply system_keyspace with
data access.
- to gain access to the wasm engine for testing whether used
defined functions compile. We'll have to find another way to
do this as well.
The change is a straightforward replacement. One case in
modification_statement had to change a capture, but everything else
was just a search-and-replace.
Some files that lost "database.hh" gained "mutation.hh", which they
previously had access to through "database.hh".
Convert the three variables in attrbutes::raw to expressions. Since
those attributes are optional, use std::optional to indicate it
(since we can't rely on shared_ptr<term::raw> being null).
The class is repurposed to be more generic and also be able
to hold additional metadata related to function calls within
a CQL statement. Rename all methods appropriately.
Visitor functions in AST nodes (`collect_marker_specification`)
are also renamed to a more generic `fill_prepare_context`.
The name `prepare_context` designates that this metadata
structure is a byproduct of `stmt::raw::prepare()` call and
is needed only for "prepare" step of query execution.
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
* Mark cql3::attributes::raw class as final
* Change every occurrence of ::shared_ptr<attributes::raw>
to std::unique_ptr<...>
* Mark all methods in cql3::attributes::raw as const
* Remove redundant "_attrs" ptr copy in insert_json_statement,
use one from raw::modification_statement
* Fix odd indentation in cql3/statements/update_statement.cc
Tests: unit-tests (dev, debug)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20200301223708.99883-1-pa.solodovnikov@scylladb.com>
`parsed_statement::get_bound_variables` is assumed to always
return a nonnull pointer to `variable_specifications` instance.
In this case using a pointer is superfluous and can be safely
replaced by a plain reference.
Also add a default ctor and a utility method `set_bound_variables`
to the `variable_specifications` class to actually reset the
contents of the class instance.
Tests: unit(dev, debug)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20200120195839.164296-1-pa.solodovnikov@scylladb.com>
Instances of `variable_specifications` are passed around as
shared_ptr's, which are redundant in this case since the class
is marked as `final`. Use `lw_shared_ptr` instead since we know
for sure it's not a polymorphic pointer.
Tests: unit(debug)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20191225232853.45395-1-pa.solodovnikov@scylladb.com>
Replace stdx::optional and stdx::string_view with the C++ std
counterparts.
Some instances of boost::variant were also replaced with std::variant,
namely those that called seastar::visit.
Scylla now requires GCC 8 to compile.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <20190108111141.5369-1-duarte@scylladb.com>
There are both marshal_exception (defined in types.hh) and
exceptions::marshal_exception (defined ini exceptions/exceptions.hh).
The latter is never thrown by anything but caught in few places which
obviously is incorrect.
Signed-off-by: Paweł Dziepak <pdziepak@cloudius-systems.com>
Convert code to use the deserialize() function and drop the duplicate
compose() wrapper that we inherited from Origin.
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
There's no benefit to using C include guards so switch to pragma once
everywhere for consistency.
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
To prepare a user-defined type, we need to look up its name in the keyspace.
While we get the keyspace name as an argument to prepare(), it is useless
without the database instance.
Fix the problem by passing a database reference along with the keyspace.
This precolates through the class structure, so most cql3 raw types end up
receiving this treatment.
Origin gets along without it by using a singleton. We can't do this due
to sharding (we could use a thread-local instance, but that's ugly too).
Hopefully the transition to a visitor will clean this up.
Initial conversion introduced a synthetic shared_ptr as the first
parameter. This deviates from Cassandra's API so switch to
enable_shared_from_this instead.
Suggested by Avi.
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
