para analisar o que quer que seja, a primeira opcao em caso de encontrar um FTS's e ir logo ou rodando um ANALYZE TABLE/DBMS_STATS ou entao sair criando indices nos campos para tentar melhorar.Ambas acoes acima descritas nao estao de todo equivocadas, mas devem serem realizadas com cautela, usando um relatorio de AWR por exemplo para identificacao com precisao das potenciais query's com problemas, ou ate mesmo utilizar a fantastica ferramenta do Oracle Cloud Control 12c e ate o bom e velho amigo Oracle GRID CONTROL.QUANDO OCORRE UM FTS's?De acordo com a Oracle, uma tabela que retorne 40% de suas linhas em caso de serem ordenadas ou 7% de suas linhas em caso de nao-ordenadas, levando em conta a chave do indice existente descrita na coluna clustering_factor da visao dba_indexes, esta consulta em si podera ser re-organizada para um uso eficiente d eum indice novo ou ja existente ao inves de usar um full-table-scan.ALL_INDEXESALL_INDEXES describes the indexes on the tables accessible to the current user. To gather statistics for this view and the related views DBA_INDEXES andUSER_INDEXES, use the SQL ANALYZE statement.Related ViewsDBA_INDEXES describes all indexes in the database.USER_INDEXES describes the indexes owned by the current user. This view does not display the OWNER column.Note:Column names followed by an asterisk are populated only if you collect statistics on the index using the ANALYZE statement or the DBMS_STATS package.ColumnDatatypeNULLDescriptionOWNERVARCHAR2(30)NOT NULLOwner of the indexINDEX_NAMEVARCHAR2(30)NOT NULLName of the indexINDEX_TYPEVARCHAR2(27) Type of the index:NORMALBITMAPFUNCTION-BASED NORMALFUNCTION-BASED BITMAPDOMAINTABLE_OWNERVARCHAR2(30)NOT NULLOwner of the indexed objectTABLE_NAMEVARCHAR2(30)NOT NULLName of the indexed objectTABLE_TYPECHAR(5) Type of the indexed object (for example, TABLE, CLUSTER)UNIQUENESSVARCHAR2(9) Indicates whether the index is UNIQUE or NONUNIQUECOMPRESSIONVARCHAR2(8) Indicates whether index compression is enabled (ENABLED) or not (DISABLED)PREFIX_LENGTHNUMBER Number of columns in the prefix of the compression keyTABLESPACE_NAMEVARCHAR2(30) Name of the tablespace containing the indexINI_TRANSNUMBER Initial number of transactionsMAX_TRANSNUMBER Maximum number of transactionsINITIAL_EXTENTNUMBER Size of the initial extentNEXT_EXTENTNUMBER Size of secondary extentsMIN_EXTENTSNUMBER Minimum number of extents allowed in the segmentMAX_EXTENTSNUMBER Maximum number of extents allowed in the segmentPCT_INCREASENUMBER Percentage increase in extent sizePCT_THRESHOLDNUMBER Threshold percentage of block space allowed per index entryINCLUDE_COLUMNNUMBER Column ID of the last column to be included in index-organized table primary key (non-overflow) index. This column maps to theCOLUMN_ID column of the *_TAB_COLUMNS data dictionary views.FREELISTSNUMBER Number of process freelists allocated to this segmentFREELIST_GROUPSNUMBER Number of freelist groups allocated to this segmentPCT_FREENUMBER Minimum percentage of free space in a blockLOGGINGVARCHAR2(3) Logging informationBLEVEL*NUMBER B*-Tree level: depth of the index from its root block to its leaf blocks. A depth of 0 indicates that the root block and leaf block are the same.LEAF_BLOCKS*NUMBER Number of leaf blocks in the indexDISTINCT_KEYS*NUMBER Number of distinct indexed values. For indexes that enforce UNIQUEand PRIMARY KEY constraints, this value is the same as the number of rows in the table (USER_TABLES.NUM_ROWS)AVG_LEAF_BLOCKS_PER_KEY*NUMBER Average number of leaf blocks in which each distinct value in the index appears, rounded to the nearest integer. For indexes that enforce UNIQUE and PRIMARY KEY constraints, this value is always1.AVG_DATA_BLOCKS_PER_KEY*NUMBER Average number of data blocks in the table that are pointed to by a distinct value in the index rounded