Many UK companies have already migrated to SAP S\/4HANA, expecting immediate performance improvements. The reason is often not SAP HANA itself \u2014 but legacy ABAP Open SQL code<\/strong> that was never designed for a column-based, in-memory database.<\/p>\n\n\n\n This article explains practical ABAP Open SQL best practices for S\/4HANA<\/strong>, focusing on performance, stability, and long-term cost efficiency<\/strong> for UK SAP teams.<\/p>\n\n\n\n SAP HANA is fundamentally different from traditional databases used in ECC systems.<\/p>\n\n\n\n Key differences:<\/p>\n\n\n\n If ABAP Open SQL is written with an ECC mindset, HANA cannot deliver its full potential \u2014 and infrastructure costs increase unnecessarily.<\/p>\n\n\n\n For UK companies running SAP in cloud environments, inefficient Open SQL directly translates to higher operating costs<\/strong>.<\/p>\n\n\n\n Using Best practice:<\/strong> This allows SAP HANA to optimise column access efficiently.<\/p>\n\n\n\n A missing or weak Best practice:<\/strong><\/p>\n\n\n\n Bad pattern:<\/p>\n\n\n\n Correct approach:<\/p>\n\n\n\n Best practice:<\/strong> Joins are optimised by HANA and scale far better for large datasets.<\/p>\n\n\n\n
However, in practice, many systems feel slower than before<\/strong>.<\/p>\n\n\n\n
\n\n\n\nWhy Open SQL Matters in S\/4HANA<\/h2>\n\n\n\n
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\n\n\n\nCore ABAP Open SQL Best Practices for S\/4HANA<\/h2>\n\n\n\n
Avoid
SELECT *<\/code> at All Costs<\/h3>\n\n\n\nSELECT *<\/code> fetches unnecessary columns, increasing:<\/p>\n\n\n\n\n
Always select only the fields you actually need.<\/p>\n\n\n\nSELECT vbeln, erdat, netwr\n FROM vbak\n INTO TABLE @DATA(lt_vbak)\n WHERE erdat >= @lv_date.\n<\/code><\/pre>\n\n\n\n
\n\n\n\nUse Proper WHERE Conditions (Early Filtering)<\/h3>\n\n\n\n
WHERE<\/code> clause often causes full table scans \u2014 one of the most common performance killers.<\/p>\n\n\n\n\n
SELECT vbeln, erdat\n FROM vbak\n INTO TABLE @DATA(lt_vbak).\n\nDELETE lt_vbak WHERE erdat < lv_date.\n<\/code><\/pre>\n\n\n\nSELECT vbeln, erdat\n FROM vbak\n INTO TABLE @DATA(lt_vbak)\n WHERE erdat >= @lv_date.\n<\/code><\/pre>\n\n\n\n
\n\n\n\nPrefer JOINs Over
FOR ALL ENTRIES<\/code><\/h3>\n\n\n\nFOR ALL ENTRIES<\/code> is still widely used in legacy UK systems, but it often produces unpredictable execution plans in S\/4HANA.<\/p>\n\n\n\n
Use database joins whenever possible.<\/p>\n\n\n\nSELECT a~vbeln, b~posnr, b~matnr\n FROM vbak AS a\n INNER JOIN vbap AS b\n ON a~vbeln = b~vbeln\n INTO TABLE @DATA(lt_result)\n WHERE a~erdat >= @lv_date.\n<\/code><\/pre>\n\n\n\n
\n\n\n\nUse Modern ABAP Syntax<\/h3>\n\n\n\n