snowshu.adapters.source_adapters.snowflake_adapter

class snowshu.adapters.source_adapters.snowflake_adapter.SnowflakeAdapter(preserve_case: bool = False)

Bases: snowshu.adapters.source_adapters.base_source_adapter.BaseSourceAdapter

The Snowflake Data Warehouse source adapter.

Parameters

preserve_case – By default the adapter folds case-insensitive strings to uppercase. If preserve_case is True,SnowShu will __not__ alter cases (dangerous!).

ALLOWED_CREDENTIALS = ('schema', 'warehouse', 'role')

DATA_TYPE_MAPPINGS = {'array': json, 'bigint': bigint, 'binary': binary, 'boolean': boolean, 'char': char, 'character': char, 'date': date, 'datetime': datetime, 'decimal': decimal, 'double': float, 'double precision': float, 'float': float, 'float4': float, 'float8': float, 'int': bigint, 'integer': bigint, 'number': bigint, 'numeric': numeric, 'object': json, 'real': float, 'smallint': bigint, 'string': varchar, 'text': varchar, 'time': time, 'timestamp': timestamp_ntz, 'timestamp_ltz': timestamp_tz, 'timestamp_ntz': timestamp_ntz, 'timestamp_tz': timestamp_tz, 'varbinary': binary, 'varchar': varchar, 'variant': json}

DEFAULT_CASE = 'upper'

MATERIALIZATION_MAPPINGS = {'BASE TABLE': TABLE, 'VIEW': TABLE}

REQUIRED_CREDENTIALS = ('user', 'password', 'account', 'database')

SNOWFLAKE_MAX_NUMBER_EXPR = 16384

SUPPORTED_FUNCTIONS = {'ANY_VALUE', 'RLIKE', 'UUID_STRING'}

SUPPORTED_SAMPLE_METHODS = (<class 'snowshu.samplings.sample_methods.bernoulli_sample_method.BernoulliSampleMethod'>,)

SUPPORTS_CROSS_DATABASE = True

static analyze_wrap_statement(sql: str, relation: snowshu.core.models.relation.Relation) → str

check_count_and_query(query: str, max_count: int, unsampled: bool) → pandas.core.frame.DataFrame

checks the count, if count passes returns results as a dataframe.

directionally_wrap_statement(sql: str, relation: snowshu.core.models.relation.Relation, sample_type: Optional[BaseSampleMethod]) → str

get_connection(database_override: Optional[str] = None, schema_override: Optional[str] = None) → sqlalchemy.engine.base.Engine

Creates a connection engine without transactions.

By default, uses the instance credentials unless database or schema override are provided.

name = 'snowflake'

static polymorphic_constraint_statement(relation: snowshu.core.models.relation.Relation, analyze: bool, local_key: str, remote_key: str, local_type: str, local_type_match_val: str = None) → str

static population_count_statement(relation: snowshu.core.models.relation.Relation) → str

creates the count * statement for a relation

Parameters

relation – the Relation to create the statement for.

Returns

a query that results in a single row, single column, integer value of the unsampled relation population size

static predicate_constraint_statement(relation: snowshu.core.models.relation.Relation, analyze: bool, local_key: str, remote_key: str) → str

builds ‘where’ strings

static quoted(val: str) → str

sample_statement_from_relation(relation: snowshu.core.models.relation.Relation, sample_type: Optional[BaseSampleMethod]) → str

builds the base sample statment for a given relation.

static union_constraint_statement(subject: snowshu.core.models.relation.Relation, constraint: snowshu.core.models.relation.Relation, subject_key: str, constraint_key: str, max_number_of_outliers: int) → str

Union statements to select outliers. This does not pull in NULL values.

static unsampled_statement(relation: snowshu.core.models.relation.Relation) → str

static upstream_constraint_statement(relation: snowshu.core.models.relation.Relation, local_key: str, remote_key: str) → str

builds upstream where constraints against downstream full population

static view_creation_statement(relation: snowshu.core.models.relation.Relation) → str