Class: MatViews::Services::CreateView

Inherits:
BaseService show all
Defined in:
lib/mat_views/services/create_view.rb

Overview

Service responsible for creating PostgreSQL materialised views.

The service validates the view definition, handles existence checks, executes ‘CREATE MATERIALIZED VIEW … WITH DATA`, and, when the refresh strategy is :concurrent, ensures a supporting UNIQUE index.

Options:

  • force: (Boolean, default: false) → drop and recreate if the view already exists

  • row_count_strategy: (Symbol, default: :none) → one of :estimated, :exact, or ‘:none or nil` to control row count reporting

Returns a MatViews::ServiceResponse

Examples:

Create a new matview (no force)

svc = MatViews::Services::CreateView.new(defn, **options)
response = svc.call
response.status # => :created or :skipped

Force recreate an existing matview

svc = MatViews::Services::CreateView.new(defn, force: true)
svc.call

via job, this is the typical usage and will create a run record in the DB

MatViews::Jobs::Adapter.enqueue(MatViews::Services::CreateViewJob, definition.id, **options)

See Also:

Constant Summary

Constants inherited from BaseService

BaseService::ALLOWED_ROW_STRATEGIES, BaseService::DEFAULT_NIL_STRATEGY, BaseService::DEFAULT_ROW_STRATEGY, BaseService::UNKNOWN_ROW_COUNT

Instance Attribute Summary collapse

Attributes inherited from BaseService

#definition, #request, #response, #row_count_strategy, #use_transaction

Instance Method Summary collapse

Methods inherited from BaseService

#call

Constructor Details

#initialize(definition, force: false, row_count_strategy: :estimated) ⇒ CreateView

Supports optional row count strategies:

  • :estimated → approximate, using pg_class.reltuples

  • :exact → accurate, using ‘COUNT(*)`

  • nil → skip row count

Parameters:

  • definition (MatViews::MatViewDefinition)
  • force (Boolean) (defaults to: false) —

    Whether to drop+recreate an existing matview.

  • row_count_strategy (Symbol, nil) (defaults to: :estimated) —

    one of :estimated, :exact, or nil (default: :estimated)



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# File 'lib/mat_views/services/create_view.rb', line 54

def initialize(definition, force: false, row_count_strategy: :estimated)
  super(definition, row_count_strategy: row_count_strategy)
  @force = force
  # Transactions are disabled if unique_index_columns are present because
  # PostgreSQL does not allow creating a UNIQUE INDEX CONCURRENTLY inside a transaction block.
  # If a unique index is required (for concurrent refresh), we must avoid wrapping the operation in a transaction.
  @use_transaction = definition.unique_index_columns.none?
end

Instance Attribute Details

#force ⇒ Boolean (readonly)

Whether to force recreation (drop+create if exists).

Returns:

  • (Boolean) 


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# File 'lib/mat_views/services/create_view.rb', line 43

def force
  @force
end