CDS Entity Buffer: Performance durch intelligentes Caching

@AbapCatalog.buffering.status: #ACTIVE
@AbapCatalog.buffering.type: #FULL
define view entity ZI_Country
  as select from t005
{
  key land1 as Country,
      waession as CurrencyKey,
      spras as Language
}

@AbapCatalog.buffering.status: #ACTIVE
@AbapCatalog.buffering.type: #FULL
define view entity ZI_Currency
  as select from tcurc
{
  key waers as CurrencyCode,
      isocd as ISOCode,
      altwr as AlternativeKey
}

@AbapCatalog.buffering.status: #ACTIVE
@AbapCatalog.buffering.type: #GENERIC
@AbapCatalog.buffering.numberOfKeyFields: 1
define view entity ZI_CompanySettings
  as select from zcomp_settings
{
  key mandt as Client,
  key bukrs as CompanyCode,
      setting_name as SettingName,
      setting_value as SettingValue
}

-- Puffert alle Einträge pro Mandant
@AbapCatalog.buffering.numberOfKeyFields: 1

-- Puffert alle Einträge pro Mandant und Buchungskreis
@AbapCatalog.buffering.numberOfKeyFields: 2

@AbapCatalog.buffering.status: #ACTIVE
@AbapCatalog.buffering.type: #SINGLE
define view entity ZI_Material
  as select from mara
{
  key matnr as Material,
      mtart as MaterialType,
      matkl as MaterialGroup,
      meins as BaseUnit
}

" Änderung über Standard-Operationen invalidiert Buffer automatisch
MODIFY zcountry FROM ls_country.

" Buffer wird beim nächsten Zugriff neu geladen
SELECT SINGLE * FROM zi_country
  WHERE country = 'DE'
  INTO @DATA(ls_de).

" Einzelnen Tabellenpuffer leeren
CALL FUNCTION 'DB_BUFFER_INVALIDATE_SINGLE'
  EXPORTING
    tabname = 'ZCOUNTRY'.

" Alle Buffer eines Bereichs leeren
CALL FUNCTION 'DB_BUFFER_INVALIDATE_AREA'
  EXPORTING
    area = 'MY_AREA'.

" Synchronisationspunkt für Buffer-Updates
CALL FUNCTION 'BUFFER_REFRESH_ALL'.

-- Basistabelle mit Buffering
@AbapCatalog.buffering.status: #ACTIVE
@AbapCatalog.buffering.type: #FULL
define view entity ZI_CountryText
  as select from t005t
{
  key land1 as Country,
  key spras as Language,
      landx as CountryName
}

-- Konsumierender View nutzt Buffer der Basis
define view entity ZI_CountryWithText
  as select from ZI_Country as Country
  left outer join ZI_CountryText as Text
    on Country.Country = Text.Country
    and Text.Language = $session.system_language
{
  key Country.Country,
      Country.CurrencyKey,
      Text.CountryName
}

" Vor dem Zugriff
DATA(lv_start) = sy-uzeit.

" Mehrfache Zugriffe (simuliert Cache-Nutzung)
DO 1000 TIMES.
  SELECT SINGLE * FROM zi_country
    WHERE country = 'DE'
    INTO @DATA(ls_country).
ENDDO.

" Zeitmessung
DATA(lv_duration) = sy-uzeit - lv_start.

-- Gut für Full Buffering: Alle Datensätze werden gebraucht
SELECT * FROM zi_currency INTO TABLE @DATA(lt_currencies).

-- Gut für Single Buffering: Einzelzugriffe
SELECT SINGLE * FROM zi_material WHERE material = @lv_matnr INTO @DATA(ls_material).

-- Schlecht für Buffering: Komplexe Abfragen mit Aggregation
SELECT SUM( amount ) FROM zi_salesdata INTO @DATA(lv_sum).

-- Interface View mit Buffering
@AbapCatalog.buffering.status: #ACTIVE
@AbapCatalog.buffering.type: #FULL
define view entity ZI_Currency
  as select from tcurc
{
  key waers as CurrencyCode,
      isocd as ISOCode
}

-- RAP Behavior Definition - Buffering wird bei Änderungen beachtet
-- managed implementation in class zbp_currency;

" Buffer-Statistiken für Tabelle
DATA: lt_buffer_stats TYPE STANDARD TABLE OF dbstattab.

CALL FUNCTION 'DB_BUFFER_STATISTICS'
  EXPORTING
    tabname        = 'ZCOUNTRY'
  TABLES
    buffer_content = lt_buffer_stats.